WO2022174264A1 - Bottom-up, scalable synthesis of oxide-based sub-nano and nanofilaments and nanofilament-based two-dimensional flakes and mesoporous powders - Google Patents

Bottom-up, scalable synthesis of oxide-based sub-nano and nanofilaments and nanofilament-based two-dimensional flakes and mesoporous powders Download PDF

Info

Publication number
WO2022174264A1
WO2022174264A1 PCT/US2022/070644 US2022070644W WO2022174264A1 WO 2022174264 A1 WO2022174264 A1 WO 2022174264A1 US 2022070644 W US2022070644 W US 2022070644W WO 2022174264 A1 WO2022174264 A1 WO 2022174264A1
Authority
WO
WIPO (PCT)
Prior art keywords
composition
quaternary ammonium
nanofilaments
phosphide
optionally
Prior art date
Application number
PCT/US2022/070644
Other languages
French (fr)
Inventor
Hussein O. BADR
Michel W. Barsoum
Original Assignee
Drexel University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Drexel University filed Critical Drexel University
Priority to JP2023548178A priority Critical patent/JP2024507122A/en
Priority to EP22753568.9A priority patent/EP4291240A1/en
Priority to CN202280021775.XA priority patent/CN117042802A/en
Publication of WO2022174264A1 publication Critical patent/WO2022174264A1/en
Priority to US18/448,593 priority patent/US20240097109A1/en

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K45/00—Medicinal preparations containing active ingredients not provided for in groups A61K31/00 - A61K41/00
    • A61K45/06—Mixtures of active ingredients without chemical characterisation, e.g. antiphlogistics and cardiaca
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present disclosure relates to the field of ID and 2D materials and to the field of metal oxide-based nanomaterials.
  • the resulting flakes are C-containing anatase-based layers that are in turn comprised of ⁇ 6 xlO A 2 nanofilaments (in some embodiments) in cross-section some of which are few microns long. Electrodes made from some of these films performed well in lithium-ion and lithium-sulphur systems. These materials also reduce the viability of cancer cells thus showing potential in biomedical applications.
  • the present disclosure provides a composition, comprising: a plurality of metal oxide (e.g., metal oxide-based) nanofilaments and/or subnanofilaments, and optionally an amount of carbon.
  • the nanofilaments can comprise titanium.
  • Example such compositions are found in “Bottom-up, scalable synthesis of anatase nanofilament-based two- dimensional titanium carbo-oxide flakes”, Badr et ak, Materials Today (2021), the entirety of which is incorporated herein by reference for any and all purposes.
  • a device comprising a composition according to the present disclosure, e.g., according to any one of Aspects 1-16.
  • compositions comprising a population of anatase nanoparticles made according to the present disclosure, e.g., according to one of Aspects 38-42.
  • a method comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non-water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting optionally performed while shaking, and the contacting being performed under conditions sufficient to give rise to mesoporous particles.
  • a method comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non-water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting optionally performed while shaking, the contacting being followed by washing with at least one salt and performed under conditions sufficient to give rise to mesoporous particles.
  • a method comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non-water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting performed while shaking and at a temperature of from about 50 to about 95 °C, followed by washing with LiCl to give rise to mesoporous particles.
  • mesoporous particles made according to the present disclosure, e.g., according to any one of Aspects 45-47.
  • compositions comprising mesoporous particles, wherein the mesoporous particles comprise titanium and wherein the mesoporous particles exhibit a XRD pattern that, when compared to a XRD pattern of nano- or bulk anatase, exhibit reduced (104) and (105) peaks at around 38° and about 55° two theta (2Q).
  • a method comprising effecting delivery of a therapeutic to a subject, the therapeutic comprising in a composition according to the present disclosure, e.g., according to any one of Aspects 48-49.
  • a method comprising effecting delivery of a therapeutic to a subject, the therapeutic comprising in a composition according to the present disclosure, e.g., according to any one of Aspects 48-49.
  • an electrode comprising a composition according to the present disclosure, e.g., according to any one of Aspects 48-49.
  • a device comprising a composition according to the present disclosure, e.g., according to any one of Aspects 48-49.
  • FIGs. 1A-1D Fabrication process, scanning electron microscope (SEM) micrographs and Density functional theory (DFT) structures.
  • FIG. 1A Schematic of fabrication process
  • FIG. IB Typical cross-sectional SEM micrograph of a TiC-derived filtered film (FF). Note undigested TiC particles in bottom right comer. Inset shows pictures of typical colloidal suspension.
  • FIG. 1C Isometric side view of 4 Ti-layered 2D anatase-based structure with TbCLC chemistry that best fits XRD and selected area diffraction (SAD) results. Blue, orange, red, and black spheres represent Ti, 2- and 3-fold coordinated O, and C respectively.
  • FIG. ID Top view of nanofilaments (nfs) growing in [200] (top) and [110] (bottom) directions.
  • Inset in (FIG. ID) compares experimental LPs (dashed lines) with DFT predictions (solid lines) as a function of number of Ti layers. Our coordinate system is shown in lower left in c and d and is not that of bulk anatase.
  • FIGs. 2A-2D Characterization of 2D material.
  • FIG. 2A XRD patterns, on log scale, of filtered, vertically oriented, TbAlC2-derived film in transmission mode. Inset shows pattern of horizontally oriented film. 5° 2Q peak is due to Kapton tape. Blue squares are 2Q locations determined from TEM-SAD patterns (Table 3).
  • FIG. 2B Raman spectrum of FF obtained from precursors indicated. All powders heated at 50 °C for 3 d and washed with ethanol and water, except the top T1B2 one that treated at 80°C for 2d. All peaks belong to anatase. [15] (FIG.
  • FIG. 3A Typical transmission electron microscope (TEM) image of TCO flake > 4 pm in lateral size. SAD of area encircled in red is shown in top right inset. Two arcs indicate fiber texture along [110] and [200] directions. Bottom inset is a higher magnification of top left comer showing frayed nanofilaments in a direction that is in accordance with the arcs.
  • FIG. 3B Scanning transmission electron microscope (STEM) showing individual filaments, the width of which is ⁇ 10 A. Bottom inset shows nanofilaments being chemically "drawn out" from a large central T13AIC2 particle.
  • FIG. 3C Atomic force microscope (AFM) of TCO self-assembled nanofilaments derived from TiC heated in TMAH at 80°C for 3d and washed with water.
  • FAM Atomic force microscope
  • FIGs. 5A-5F SEM micrographs of FFs’ cross sections after ethanol and LiCl washing made starting with, (FIG. 5A) Ti3SiC2, (FIG. 5B) T13AIC2, (FIG. 5C)
  • TriSbP (FIG. 5D) TiN, (FIG. 5E) T1B2, and (FIG. 5F) TriSri. Insets show corresponding colloidal suspensions and FFs.
  • FIGs. 6A-6C X-ray diffractograms (shifted vertically for clarity) of FF from
  • FIG. 6A Parent TiC, T13AIC2, TriSiC2 precursors (black lines), and their derived 2D TCO films (red, blue, and green curves, respectively) after washing with ethanol and without sonication.
  • FIG. 6B TiC (red, bottom), T13AIC2 (blue, middle), and TriSiC2 (green, top) derived films after washing with ethanol then LiCl solution.
  • FIG. 6C T1B2 (red, bottom), TiN (blue, middle), and TriSri (green, top), derived films after washing with ethanol then LiCl solution.
  • FIG. 7A Setup used to obtain XRD patterns from vertically oriented films in transmission mode. Inset shows Kapton tape with drop cast film taped to vertical aluminum sample holder.
  • FIG. 7B XRD patterns (shifted vertically for clarity) of vertically aligned ethanol washed FF, derived from precursors indicated.
  • TMAH TMAH
  • TiC powders were immersed in the TMAH at 50°C for lid (blue, top).
  • XRD characterization 1-1.5 ml of colloidal suspension was drop cast on Kapton tape using a pipette then air dried. Black vertical line at 5° originated from the Kapton tape. Blue lines are guides to the eye to the anatase-based 2D structure.
  • FIGs. 8A-8F Typical TEM images of (FIG. 8A) and (FIG. 8B) TiC- derived flakes (50 °C, 3d) (FIG. 8C) Same as (FIG. 8A) but TiC was heated to 80°C for 3d emphasizing the fibrous nature of our TCO flakes.
  • FIG. 8D nanofilaments crystallizing from an amorphous TCO background. Inset reveals high resolution image of crystalline nanofilaments 2-3 nm wide and few microns long. In the previous cases, reaction products were water washed.
  • FIG. 8E Ti3SiC2-derived flakes (50°C for 3d, washed with ethanol) captured from crushed FF.
  • FIG. 8F Nanofilaments appearing to be chemically “drawn” from T13AIC2 phase (dark particle in center) (50°C, 3d; washed with ethanol and water). Insets show SAD pattern from area bounded by red circles. Inset in f show both faint rings (from TCO) and MAX phase spots.
  • FIG. 10A 6-layered anatase structure.
  • Slab thickness is ⁇ 8 A.
  • FIG. 10B Phonon density of states of 4-layered structure shown in Fig. lc.
  • Fig. 11 Post LiCl-washed XPS spectra of Ti 2p region (1 st column), C Is region (2 nd column), O Is region (3 rd column) and Fermi edge (4 th column) obtained from TiC- (1 st row, top) , T13AIC2- (2 nd row), Ti3SiC2- (3 rd row), TiN- (4 th row), T1B2- (5 th row), and TiCh-based (6 th row) films. Peak fits and results are summarized in Tables 4 and 7. Dashed vertical lines are guides to the eye. [0035] Figs. 12A-12B.
  • XPS spectra as a function of processing in Ti 2p region (1 st column), C Is region (second column), O Is region (third column), and Fermi edge (last column) of, (FIG. 12A) T13AIC2 -based and, (FIG. 12B) TriSiC2 -based filtered films. Dashed vertical lines are guides to the eye. Notably positions of Ti peaks appear to be insensitive to solution used to wash the films and even after heating to 800 °C in Ar in the T13AIC2 case (compare top spectra in blue to those below them in a).
  • FIGs. 13A-13E XPS spectra of TCO FF for (FIG. 13A) N Is and, (FIG. 13B) Cl 2p regions derived from TiC (black, bottom), T13AIC2 (red, second from bottom) Ti3SiC2(blue, third from bottom), TiN (green, third from top), T1B2 (purple, second from top) and T1O2 (yellow, top) powders, (FIG. 13C) Si 2p spectra the Ti3SiC2-derived FF, (FIG. 13D) A12p spectra for Ti3AlC2-derived FF, (FIG. 13E) B is spectra for T1B2- derived FF. All samples were washed with ethanol and LiCl before filtration, followed by vacuum drying before XPS analysis.
  • FIG. 14A Thermogravimetric plots for, (FIG. 14A) All samples, ramped at 10 °C/min to 800 °C in Ar. Sample labeled ethanol was washed with ethanol; those labeled LiCl were first washed with ethanol and then with a LiCl solution. (FIG. 14A)
  • Fig. 15 Rietveld analysis of XRD diffractograms of LiCl washed filtered films heated to 800 °C in Ar. The c 2 values are listed on figures. Results are summarized in Table 8. Purple lines are differences between fits in red and experimental results in black.
  • FIG. 16A XRD diffraction patterns of TiCh-derived material heated in TMAH for times and temperatures indicated on figure. In the 2D anatase the (104 and (105) peaks are absent and the 63° peak is shifted towards 60°.
  • FIG. 16B TEM of anatase nanoparticles in the range of 20 nm. Insets show high magnification image and SAD pattern of the obtained T1O2 nanoparticles.
  • FIGs. 17A-17D Electrochemical performance of Ti3AlC2-based TCO as electrode materials in Li-ion battery.
  • FIG. 17A Electrochemical impedance spectroscopy Nyquist plot at open circuit potential
  • FIG. 17B Specific capacity vs. cycle number and specific currents indicated.
  • FIG.17C Voltage profile at specific current of 100 mA g 1 .
  • FIG. 17D Specific capacity and Coulombic efficiency vs. cycle number for cell shown in c.
  • FIGs. 18A-18B Electrochemical characterization of TiC-based FF electrode in Li-S cell: (FIG. 18A) CV curves, (FIG. 18B) Cycling stability at 0.2 C. S- loading is 0.8 mg. Capacity was, more or less, constant at ⁇ 1000 mAh/g for about 300 cycles before fading.
  • Fig. 19 provides images of exemplary mesoscopic materials according to the present disclosure.
  • Table 1 provides sources of example powders and reagents used in this work.
  • Table 2 provides a summary of example precursors, TkTMAH mole ratios, and synthesis conditions.
  • Table 3 provides a summary of interlayer spacing (d) values and the corresponding diffraction angle (2Q) acquired from XRD pattern shown in Fig. 2a and their comparison to those obtained from 7 different SAD patterns obtained from 5 different samples. All samples derived from parent TiC heated at 50°C then washed with ethanol and water.
  • Table 4 provides a summary of fitting of XPS results shown in Fig. 11.
  • Table 5 provides chemistries of 5 different flakes deduced from EELS measurements shown in Fig. 2c. Last row suggests possible chemistries where X sum of O, C and N. Flakes were prepared by dry rubbing filtered films made by heating TiC powders in TMAH for 3d at 50°C, then washed with ethanol.
  • Table 6 provides chemistries of number of flakes from different precursors deduced from EDS measurements. Last row suggests possible Ti:0 ratios of these samples.
  • SEM-EDS measurements were obtained from cross-sections of filtered films made of the precursor T13AIC2, Ti3SiC2, Ti3GaC2 powders reacted with TMAH at 50°C for 72h and washed with ethanol then a LiCl solution.
  • TEM-EDS measurements were conducted on samples prepared by dry rubbing Ti3SiC2- and TiB2-derived filtered films made by reacting the powder with TMAH at 50°C for 72h and washing with ethanol.
  • Table 7 provides Ti:0 chemistries obtained from the Ti area under ⁇ 459 eV peak and O under ⁇ 530 eV peak shown in Fig. 11.
  • Table 8 provides a summary of Rietveld analyses of filtered films after heating in Ar to 800°C. Corresponding XRD patterns are plotted in Fig. 15.
  • the term “comprising” can include the embodiments “consisting of and “consisting essentially of.”
  • the terms “comprise(s),” “include(s),” “having,” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that require the presence of the named ingredients/steps and permit the presence of other ingredients/steps.
  • compositions or processes as “consisting of and “consisting essentially of the enumerated ingredients/steps, which allows the presence of only the named ingredients/steps, along with any impurities that might result therefrom, and excludes other ingredients/steps.
  • the terms “about” and “at or about” mean that the amount or value in question can be the value designated some other value approximately or about the same. It is generally understood, as used herein, that it is the nominal value indicated ⁇ 10% variation unless otherwise indicated or inferred. The term is intended to convey that similar values promote equivalent results or effects recited in the claims. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but can be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art.
  • an amount, size, formulation, parameter or other quantity or characteristic is “about” or “approximate” whether or not expressly stated to be such. It is understood that where “about” is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise.
  • approximating language can be applied to modify any quantitative representation that can vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about” and “substantially,” may not be limited to the precise value specified, in some cases. In at least some instances, the approximating language can correspond to the precision of an instrument for measuring the value.
  • the modifier “about” should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4.” The term “about” can refer to plus or minus 10% of the indicated number.
  • compositions that comprises components A and B can be a composition that includes A, B, and other components, but can also be a composition made of A and B only. Any documents cited herein are incorporated by reference in their entireties for any and all purposes.
  • TMAH acts as a near-universal solvent that dissolves the precursor and releases Ti atoms that spontaneously react with C and O in the TMAH/water to form 2D flakes comprised of self-assembled nanofilaments (see below).
  • the TMAH role is thus twofold: solvent and templating agent.
  • a X-ray diffraction (XRD) pattern of a Ti3AlC2-derived film after ethanol washing is typical of 2D materials.
  • XRD patterns of dry FF obtained from other precursors are shown in Fig. 6. The absence, for the most part, of peaks associated with the precursors is noteworthy.
  • Fig. 2a X-ray diffraction
  • the red vertical lines were obtained as follows: First, the c-lattice parameter, LP, was calculated from horizontally oriented film (inset in Fig. 2a). The structure shown in Fig. lc was then used to calculate the position of all peaks. All planes with non-zero t indices were eliminated, leaving the red lines. The good agreement between the density functional theory (DFT) generated LPs and the experimental ones (inset in Fig. Id) lends credence that we are dealing with a 4 Ti-layered anatase-based 2D material (see below). Patterns for other vertically oriented films, derived from other precursors, are shown in Fig. 7b. In all cases, peaks - with identical angles - were obtained. This is crucial and cannot be overemphasized since it demonstrates that precursor chemistry does not alter the structures formed, including their LPs.
  • DFT density functional theory
  • One set of arcs indicated that the long axis of the nanofilaments is in the [110] direction; the other in the [200] direction. The angle between them is shown in both inset and main micrograph. They are in the same directions as the frayed fibers seen at the sheet edges in top left.
  • the scanning transmission electron microscope (STEM) micrograph (Fig. 3b) clearly shows the fibrous nature of the sample.
  • the width of individual nanofilaments is estimated to be ⁇ 1 nm. Since their thickness is ⁇ 5.9 A, it follows that we are dealing with nanofilaments roughly 6 xlO A 2 in cross-section that can be micrometers long (see inset in Fig 3b and Fig. 8c).
  • Other TEM micrographs are shown in Fig. 8. We note in passing theoretical surface area of these nanofilaments is ⁇ 1500 m 2 /g.
  • Figure 3c and Figure 9 show TEM and atomic force microscope (AFM) maps of a TiC-derived sample (5d at 80°C, water washed), spin coated on glass. The fibrous nature of the product and its tendency for self-alignment are obvious.
  • AFM atomic force microscope
  • the LPs of the b axes of the three structures are in good agreement with experimental values especially given that the DFT calculations were performed at 0 K.
  • a large increase in the a-LP is observed - that is closer to the experimental values - when the number of Ti layers increases to 4 or 6 (blue curves in inset in Fig. Id).
  • the thicknesses of the 4- and 6-layered anatase are - 5.9 A and ⁇ 8 A. respectively.
  • the diameter of a TMA cation ranges from 4.5-6 A [17, 18] Using the low end, the ri-spacing between filaments for the 4- and 6-layered structures would be 10.4 A and 12.5 A, respectively.
  • Fig. 8d is a snapshot of how, in certain regions, the nanofilaments self-align to form "crystalline" regions.
  • Films derived from TiC and the MAX phases were conductive, with conductivities in the range of 0.01 to 0.05 S/cm; those made with T1O2 and T1B2 are not. These conductivities are roughly 5 to 6 orders of magnitude lower than MXenes, that range from 2,000 to 25,000 S/cm, but notably orders of magnitude higher than typical oxides, especially the more common version of layered titanates, viz. lepidocrocites.[23- 25] The conductivity is not always present and suggests an unknown variable is at play that is currently being investigated.
  • Li-S Lithium sulfur
  • an additional step of washing with LiCl solution was conducted and the produced flakes were characterized.
  • a 5M LiCl solution was added to the black colloidal suspension obtained above. This resulted in deflocculation.
  • the sediment was shaken and rinsed with deionized water through centrifugation at 5000 rpm for three cycles.
  • the LiCl/DI water washing process was repeated until the pH was - 7.
  • the washed sediment was then sonicated in a cold bath for 1 h under flowing Ar, shaken for 5 min, then centrifuged at 3500 rpm for 10 min.
  • the colloidal suspension was filtered to produce FFs. The FFs were then left to dry in a vacuum chamber overnight before further characterization.
  • the black slurry - produced from the reaction of TMAH and TiC - centrifuged (at 5000 rpm for 5 min) directly without the addition of any solvents, the supernatant decanted, the sediment resuspended in 20 mL DI water, shook for 5 min, then centrifuged at 3500 rpm for 30 min.
  • the produced black colloidal suspension was used for XRD (not shown) and TEM inspection.
  • the yield was calculated as fraction of the number of moles of Ti in the produced anatase-like structure (molar mass of TiCh is used for simplicity) to those supplied by the precursor. For instance, the yields for TiC and T13AIC2 are 19% and 28%, respectively. In general, the yield is of the order of - 20% depending on starting precursor.
  • the solid loading in our colloidal suspensions is of the order of 10 g/L.
  • XRD patterns on air dried samples were acquired using a powder diffractometer (Rigaku SmartLab) setup in the Bragg-Brentano geometry with Cu Ka radiations in the 2-65° 2Q range using a 0.02° step size and a dwell time of 1 s/step.
  • Raman scattering spectra were collected at 300 K in air from FF of a number of precursors (Fig. 2b). The samples were probed using a 532- nm laser emitting 3.75 mW of power at the sample and focused to a spot diameter of -0.5 pm. Scattered light was collected in a backs cattering geometry and was dispersed and detected using a single-axis monochromator equipped with a charge-coupled detector array (Horiba XploRA, Edison NJ)
  • XPS was performed using a spectroscope (VersaProbe 5000, Physical Electronics, Chanhassen, Minnesota). Monochromatic Al-Ka X-rays with a 200 pm spot size were used. A pass energy of 23.5 eV, with an energy step of 0.05 eV and a step time of 0.5 s was used to gather high-resolution spectra. Number of repeats per scan was 10. XPS spectra were calibrated by setting the major C-C peak to 285.0 eV. Peaks were fit using asymmetric Gaussian/Lorentzian line shapes. The background was determined using the Shirley algorithm. All samples were mounted on a XPS stage using carbon tape.
  • Thicknesses of filaments and flakes were obtained with an AFM (Multimode 8 AFM from Bruker Nano Surfaces). A peak force tapping AFM imaging mode was applied to acquire the surface morphology and height profiles. The scanning was conducted with ScanAsyst-Air Silicon Nitride Probes at a scan rate of 0.6 Hz. Topographic images were recorded as the resolution of 256*256 pixels and analyzed by Nano Scope Analysis software.
  • TEM imaging and electron diffraction patterns were collected using a JEOL JEM2100F field-emission TEM.
  • the TEM was operated at 200 keV and has an image resolution of 0.2 nm.
  • Images and diffraction patterns were collected on a Gatan USC1000 CCD camera.
  • Scanning transmission electron microscopy, STEM was carried out in the monochromated and double Cs corrected FEI Titan3 60-300 operated at 300 kV.
  • STEM-EELS spectra were acquired by averaging 100 spectra, acquired for 1 s each at a 0.25 eV/channel energy dispersion, and collection semi-angle of 55 mrad of employed Gatan GIF Quantum ERS post-column imaging filter. Elemental quantification of present edges was performed using built in functions of Digital Micrograph. [00103] X-ray absorption near edge structure, XANES
  • the Ti K-edge isotropic XANES spectra were recorded at 54° from the normal to the film using circularly polarized x-rays provided by the first harmonic of the HELIOS-II type helical undulator (HU-52).
  • the x-ray beam was monochromatized using a fixed-exit double crystal monochromator equipped with a pair of Si(l 11) crystals.
  • Total fluorescence yield signal was collected by a Si photodiode mounted in back-scattering geometry. Spectra were corrected for self-absorption effects.
  • the samples were ⁇ 1 mm thick compressed powered pellets.
  • the isotropic XANES spectra were normalized to an edge jump of unity far above the absorption edge.
  • the photon energy scale was calibrated using the pre-peak maximum in the absorption spectrum of a Ti thin foil that was set to 4965.6 eV. Spot size was 0.4x0.3 mm 2 . Experiments were performed at European Synchrotron Radiation Facility (ESRF) ID12 beamline in Grenoble
  • thermobalance (TA Instruments Q50, New Castle DE) was used for the TGA analysis. Small pieces of FF ( ⁇ 20 mg) were heated in sapphire crucible at 10 °C/min, under purging Ar at 10 mL/min, to 800 °C. In one experiment we used a thermobalance attached to a mass-spectrometer. In these measurements a thermal analyzer (TA instruments, SDT 650, Discovery Series) coupled with a mass spectrometer (TA instruments Discovery Series) operating at 40 V ionizing potential was used. Samples were held at RT for 0.5 h then heated to 800°C at 10°C/min under dry compressed air flow at 50 mL/min. The carrier gasses and evolved gas products from the sample were measured by scanning over the 1-100 atomic mass unit range. The ion current for each m/z (mass/charge ratio) was normalized by the initial sample weight.
  • UV-VIS spectra were recorded using spectrophotometer (Evolution 300 UV -Visible, Thermo Scientific). Measurements were performed in transmission mode on 1-1 Opm thick films coated onto quartz slides. [00111] DFT calculations
  • the electronic configurations of the pseudopotentials used were C: [He]2S 2 2P 2 , O: [He]2s 2 2p 4 and Ti_sv: [Ne]3s 2 3p 6 3d 2 4s 2 .
  • the calculation supercells were constructed to consist of various anatase (101) atomic layers using a slab model, with periodicity along the a and b axes of the supercell, which correspond to the [100] and [101] directions of bulk anatase, respectively.
  • the supercell geometry and atom positions were relaxed until the force on each atom ⁇ 5 meV/A.
  • a vacuum region of 15 A was added along the oaxis (in new coordinate system) of the supercell to eliminate interactions between periodic images perpendicular to the slabs.
  • the first Brillouin zone was sampled by a 16x6x1 k-point sampling, while a 8x3x1 supercell together with a 2x2x1 k-point sampling was used for the phonon
  • TCO electrochemical performance of TCO as electrode material as LIB material
  • the TCA working electrodes were fabricated by drop-casting a slurry of active materials with binder and carbon additive on a carbon coated copper foil.
  • the slurry was prepared by mixing 40.0 mg of active materials, 5.0 mg of poly(vinylidene fluoride) (PVDF, Sigma Aldrich, US) binder in N-methyl-2-pyrrolidinone (NMP, 99.5%, Acros Organics, Extra Dry over Molecular Sieve, Germany) solvent, and 5.0 mg of carbon black.
  • PVDF poly(vinylidene fluoride)
  • NMP N-methyl-2-pyrrolidinone
  • the as-prepared electrodes were dried overnight at 60 °C.
  • the electrode mass loading was ⁇ 1.2- 1.5 mg/cm 2 .
  • Two-electrode CR2032-type coin cells were assembled in an Ar-filled glovebox with O2 and H2O ⁇ 0.1 ppm. Li metal foil was used as a counter electrode. 1M L1PF6 in ethylene carbonate (EC)/ ethyl methyl carbonate (EMC) with 3:7 (by weight) and glass fibers were used as electrolyte and separator, respectively.
  • CV and galvanostatic charge- discharge testing were performed with a cut-off electrochemical voltage window of 0.001- 3.0 V vs Li/Li + using an electrochemical workstation (BioLogic VMP3) and a cycler (Landt CT2001A,). Electrochemical impedance spectroscopy with frequency from 100 kHz to 10 mHz were conducted in a electrochemical workstation (BioLogic VMP3).
  • TCO/S cathodes using a slurry-based method. Briefly, the slurry was prepared by mixing 35 wt% vacuum-dried TCOs, 35 wt% sulphur, S, with 20 wt% conductive carbon (Alfa Aesar, Super P) and 10 wt.% battery grade PVDF binder (MTI Corp., USA). The materials were hand-ground with a mortar and pestle until the mixture appeared uniform. Later, N-Methyl-2-pyrrolidone (TCI, USA) was slowly added until the required visible consistency and uniformity of the slurry were achieved ( ⁇ 25 minutes).
  • TCI N-Methyl-2-pyrrolidone
  • the slurry was later cast on aluminum foil using a doctor blade (MTI Corp., USA) with a thickness of 20 pm. Once cast, the slurry was kept in a closed fume hood for 2 h before transferring to a vacuum oven where it was dried at 50 °C for 12 h.
  • the dried TCO/S cathodes were cut using a hole punch (diameter 11 mm) to form disks.
  • the electrodes were then weighed and transferred to an Ar-filled glove box (MBraun Lab star, O2 ⁇ 1 ppm, and H2O ⁇ 1 ppm).
  • the CR2032 (MTI Corporation and Xiamen TMAX Battery Equipment) coin-type Li-S cells were assembled using TCO/S cathodes, a 15.6 mm diameter, 450 pm thick Li disk anode (Xiamen TMAX Battery Equipment) a tri-layer separator (Celgard 2325), and a stainless-steel spring and two spacers along with the electrolyte.
  • the electrolyte with 1 M LiTFSi with 1 wt% L1NO3 in a mixture of 1,2-dimethoxy ethane and 1,3-dioxolane at a 1:1 volume ratio, was purchased (TMAX Battery Equipment, China) and according to manufacturer contained trace amounts of oxygen and moisture (H2O ⁇ 6 ppm and O2 ⁇ 1 ppm). Assembled coin cells were rested at their open-circuit potential for 10 h before performing the electrochemical experiments at RT. Cyclic voltammetry was performed at a scan rate of 0.1 mV.s 1 between voltages 1.8 and 2.6 V wrt Li/Li + using a potentiostat (Biologic VMP3).
  • the Li-S cells were conditioned for 2 cycles at 0.1 C and 0.2 C, before undergoing long cycling at 0.5 C.
  • the TEM images show that the aligned regions are a fraction of the total. In a sizable fraction, the nanofilaments are not aligned, but randomly oriented in the plane of the flakes. This has also been confirmed by selected area diffraction pattern (SAD) that showed diffraction rings for most of the characterized flakes.
  • SAD selected area diffraction pattern
  • FIG. 2c The EELS spectra on 5 different particles were measured on TiC-based flakes obtained after heating in TMAOH for 3d at 50 °C and ethanol washed.
  • Figure 2c includes carbon -K edge at -280 eV energy loss, titanium -L3,2 peaks at -450 eV energy loss and oxygen -K edge at -530 eV energy loss. All spectra are normalized to the Ti edge peak intensity. Thicker particles exhibit a steeper background, which is more easily seen at the low energy of the spectrum. The top and bottom spectra exhibit a pronounced lower intensity compared to the three particles in the middle.
  • the top and bottom spectra contain approximately the same amount of C, while for the three in the middle (2, 3 and 4) the chemistry was consistent aTi:C:0 atomic ratio of- 1:1:1. All spectra also show a minor amount of N-K (not shown) at -400 eV energy loss. For the remainder of this paper, this small amount of N will be ignored.
  • the results of these spectra are summarized in Table 5. The C is presumed to be in the backbone of the structure because the intensity of the C-loss peak did not change with time under the electron beam.
  • Typical XPS spectra of all films are compared in Figure 11. The peaks were fit and the results are summarized in Table 4. The Ti:0 ratios of the films are summarized in Table 7. The latter were obtained from the areas of the Ti peaks at ⁇ 459 eV peak and the O peaks at ⁇ 530 eV peak. Here the ratio is roughly 1:3.
  • the BEs after ethanol washing, LiCl and even after TGA to 800 °C are all quite comparable indeed and thus the values obtained on these films can be considered representative of all BEs for all processing conditions.
  • the films were heated in air the XPS spectra shifted (not shown).
  • Fig. 13 shows that, except in the case of TriSiC2 for which a Si signal was observed (Fig. 13c), all other films were comprised of only three elements, Ti, O and C. There was also no Cl between the layers confirming that we are not dealing with double layered hydroxides (Fig. 13b).
  • T1O2 is an outlier is because we have shown by XRD and TEM (Fig. 16) that what forms in this case is not a 2D structure, but rather nano-anatase particles. It is instructive at this point to compare the XRD diffraction patterns of anatase and our 2D flakes. In the latter the (104) and (105) peaks do not exist and the 63° 20 peak in anatase shifts much closer to 60° 20 (Fig. 16a).
  • Figure 4b in main paper shows the galvanostatic charge/discharge voltage profiles at a specific current of 20 mA g 1 , the initial lithiation and delithiation specific capacities are 714 and 265 mAh g 1 , respectively.
  • the specific capacity loss in the first lithiation process can be attributed to the solid electrolyte interphase (SEI) layer formation below 0.85 V and other irreversible reactions.
  • SEI solid electrolyte interphase
  • the specific capacity stabilizes after two cycles.
  • the stable lithiation and delithiation specific capacities of 210 and 209 mAhg 1 , respectively, are maintained after 5 cycles.
  • Figure 17a plots the electrochemical impedance spectroscopy of the electrode, showing low system resistance (4 W) and small charge transfer resistance (18 W), which support the electrochemical performance observed. Rate handling capability results are shown in Figure 17b.
  • a reversible capacity of - 110 mAh g _1 can be maintained.
  • a reversible capacity of - 80 mAh g 1 can be achieved, and by returning to 20 mA g 1 , the capacity recovered to -180 mAh g 1 .
  • the as-prepared TCO electrode exhibits excellent cycling stability performance at a specific current of 100 mA g 1 .
  • the electrode shows a specific capacity of 155 mAhg 1 over 200 cycles.
  • the Coulombic efficiency of the electrode is - 98.9% after 30 cycles, reflecting a highly efficient electrochemical cycling.
  • FIG 18a plots typical CV curves in the 1.8-2.6 V (vs. Li/Li + ) range at a scan rate of 0.1 mV s 1 .
  • the CV curves show two sharp and distinct cathodic and one anodic peak.
  • the first cathodic peak at 2.3 V is ascribed to S reduction (12) to long-chain lithium polysulfides (LiPs), while the second peak is related to a subsequent reduction of LiPs to Li26/Li2S.[17]
  • the peak shifts after the first anodic peak are possibly due to nucleation/reorganization during the redeposition of the LiPs back to 12.
  • Figure 4c displays typical discharge plateaus consistent with the CV results.
  • the TCO/S composite electrodes deliver capacities of 1300, 1200, 1050 mAh g 1 at 0.1, 0.2 and 0.5 C rates, respectively. Such high capacity can be associated with the TiCO conductivity, coupled with possible surface-active sites that bind to the LiPs.
  • Figure 14b shows the cell delivers an initial capacity of -1300 mAh g 1 , which stabilizes to -1000 mAh g 1 after the first 5 cycles. This initial drop is associated with the two conditioning cycles at low rate of 0.1 and 0.2 C.
  • the composite delivers a capacity of -1000 mAh g 1 after ⁇ 300 cycles with around 100 % retention. The capacity drops after 300 cycles.
  • XRD pattern of the powder showed low angle peak with d-spacing of 9.4 A, non-basal peaks at 25° and 48°, that correspond to 2D anatase. The (104) and (105) peaks were missing. Some low intensity peaks that belong to unreacted the TiB2 precursor remained.
  • SEM micrographs (Fig. 19) of the resulting powder revealed an even distribution of well separated mesoporous particles roughly 10 pm in size.
  • the mesoporous particles can be made of ligaments that are few-mi crons long and less than 100 nm in diameter.
  • the mesoporous particles can be used in, e.g., drug delivery, energy storage, and devices.
  • a therapeutic can be associated with the mesoporous particles (e.g., adsorbed to, intercalated into, etc.), which therapeutic-laden particles can be introduced to a subject and deliver the therapeutic to the subject.
  • a composition comprising: a plurality of oxide-based nanofilaments and/or subnanofilaments, and optionally an amount of carbon.
  • the nanofilaments can comprise titanium.
  • the composition can be present as a mesoporous powder in which the powder particulates comprise the oxide- based nanofilaments and/or subnanofilaments.
  • Aspect 2 The composition of Aspect 1, wherein at least some of the nanofilaments and/or subnanofilaments have a width in the range of from about 3 to about 50 A.
  • the width can be, e.g., from about 3 to about 50 A, from about 5 to about 45 A, from about 7 to about 40 A, from about 9 to about 35 A, from about 12 to about 30 A, from about 15 to about 20 A, and all intermediate values and combinations.
  • the composition can be comprised in a suspension, e.g., in a solution or an ink, which ink can be printable.
  • inks can be sprayed, printed, or otherwise applied to a substrate.
  • An ink can include solvents, binders, and the like.
  • Aspect 3 The composition of Aspect 2, wherein at least some of the nanofilaments and/or subnanofilaments have an average width in the range of from about 7 to about 20 A.
  • Aspect 4 The composition of any one of Aspects 1-3, wherein the nanofilaments and/or subnanofilaments define anon-circular cross-section.
  • Aspect 5 The composition of Aspect 4, wherein the nanofilaments and/or subnanofilaments define a cross-sectional aspect ratio of from greater than 1 to about 10.
  • the cross-sectional aspect ratio can be from 1.1 to 10, from 1.5 to 9, from 1.8 to 8, from 2.2 to 7, from 2.5 to 6, from 2.8 to 5, or even from 3.2 to 4.
  • Aspect 6 The composition of Aspect 5, wherein the nanofilaments and/or subnanofilaments define a cross-sectional aspect ratio of from about 2 to about 5.
  • Aspect 7 The composition of any one of Aspects 1-6, wherein the nanofilaments and/or subnanofilaments have an average cross-sectional area in the range of from about 10 to about 100 A 2 .
  • the average cross-sectional area can be the range of from about 10 to about 100 A 2 , from about 15 to about 90 A 2 , from about 20 to about 80 A 2 , from about 30 to about 70 A 2 , from about 40 to about 60 A 2 , or even about 50 A 2 .
  • Aspect 8 The composition of any one of Aspects 1-7, wherein at least some of the nanofilaments and/or subnanofilaments have a length in the range of from 1 nm to about 25 pm.
  • the length can be, e.g., from about 1 nm to about 25 pm, from about 10 nm to about 20 pm, from about 50 nm to about 10 pm, from about 100 nm to about 5 pm, or from about 250 nm to about 2 pm.
  • Aspect 9 The composition of Aspect 8, wherein at least some of the nanofilaments and/or subnanofilaments have a length in the range of from 1 nm to about 1 pm.
  • Aspect 10 The composition of any one of Aspects 1-9, wherein the nanofilaments and/or subnanofilaments are comprised in a plurality of flakes; the nanofilaments and/or subnanofilaments can self-assemble into the flakes.
  • the nanofilaments and/or subnanofilaments can be aligned in a plane; and a flake can include two or more layers of aligned nanofilaments and/or subnanofilaments, which can in turn provide a flake that is a well-ordered stack of nanofilament and/or subnanofilament layers.
  • the nanofilaments can be self-aligning.
  • Aspect 11 The composition of Aspect 7, wherein at least some of the plurality of flakes lie in a common plane.
  • the flakes can be well-stacked along the stacking direction.
  • the nanofilaments and/or subnanofilaments can result in in XRD patterns that are typical of 2D materials, i.e., only one family of planes diffract. Without being bound to any particular theory or embodiment, the nanofilaments and/or subnanofilaments can self-assemble into 2D flakes.
  • Aspect 12 The composition of any one of Aspects 1-11, further comprising a pharmaceutically acceptable carrier.
  • Aspect 13 The composition of any one of Aspects 1-12, further comprising one or more materials that are fatal to cancer cells.
  • Aspect 14 The composition of any one of Aspects 1-13, further comprising a binder.
  • a binder can be, e.g., a glue, an adhesive, or other matrix material.
  • Aspect 15 The composition of Aspect 14, wherein the binder comprises a polymer.
  • Aspect 16 The composition of any one of Aspects 1-15, wherein the nanofilaments and/or subnanofilaments exhibit a XRD pattern that, when compared to a XRD pattern of nano- or bulk anatase, exhibit reduced (104) and (105) peaks at around 38° and about 55° two theta (2Q).
  • the disclosed nanofilaments and/or subnanofilaments can, in some embodiments, exhibit a Raman spectrum that is quite similar to that of bulk anatase, but can differ from bulk anatase in terms of the XRD spectrum, as described herein.
  • Aspect 17 A device, the device comprising a composition according to any one of Aspects 1-16.
  • Aspect 18 The device of Aspect 17, wherein the device comprises an electrode.
  • Aspect 19 The device of Aspect 17, wherein the device is characterized as an energy storage device.
  • a device can be, e.g., a battery, a supercapacitor, and the like.
  • a device can be rechargeable, but can also be disposable.
  • Such a device can be comprised in a mobile computing device, a mobile communications device, a computing device, an illumination device, a signal transmitted, a signal receiver,
  • Aspect 20 The device of Aspect 18, wherein the electrode comprises a composition according to any one of Aspects 1-16.
  • Aspect 21 The device of Aspect 17, wherein the device comprises a dispenser, the dispenser having disposed therein the composition according to any one of Aspects 1-16.
  • a dispenser can be, e.g., a syringe, a nozzle, and the like.
  • Such a dispenser can be used to deliver the composition (e.g., according to any one of Aspects 1-16) to a subject (e.g., a human patient) and/or to a sample obtained from a patient.
  • a sample can be, e.g., a blood sample.
  • Aspect 22 A method, comprising operating a device according to Aspect 17.
  • a method comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non- water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting being performed under conditions sufficient to give rise to a nanofilamentous (and/or subnanofilamentous) product.
  • the product can self-assemble into 2D flakes.
  • Example carbides include, e.g., titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, niobium carbide, tantalum carbide, chromium carbide, molybdenum carbide, tungsten carbide, iron carbide, and the like.
  • Example nitrides include, e.g., aluminum nitride, boron nitride, calcium nitride, cerium nitride, europium nitride, gallium nitride, indium nitride, lanthanum nitride, lithium nitride, magnesium nitride, niobium nitride, silicon nitride, strontium nitride, tantalum nitride, titanium nitride, vanadium nitride, zinc nitride, zirconium nitride, and the like.
  • Example borides include, e.g., aluminium diboride, aluminium dodecaboride, aluminium magnesium boride, barium boride, calcium hexaboride, cerium hexaboride, chromium(III) boride, cobalt boride, dinickel boride, erbium hexaboride, erbium tetraboride, hafnium diboride, iron boride, iron tetraboride, lanthanum hexaboride, magnesium diboride, nickel boride, niobium diboride, osmium boride, plutonium borides, rhenium diboride, ruthenium boride, samarium hexaboride, scandium dodecaboride, silicon boride, strontium hexaboride, tantalum boride, titanium diboride, trinickel boride, tungsten boride, uran
  • Example phosphides include, e.g., alminium gallium indium phosphide, aluminium gallium phosphide, aluminium phosphide, bismuth phosphide, boron phosphide, cadmium phosphide, calcium monophosphide, calcium phosphide, carbon monophosphide, cobalt(II) phosphide, copper(I) phosphide, dysprosium phosphide, erbium phosphide, europium(III) phosphide, ferrophosphorus, gadolinium phosphide, gallium arsenide phosphide, gallium indium arsenide antimonide phosphide, gallium phosphide, holmium phosphide, indium arsenide antimonide phosphide, indium gallium arsenide phosphide, indium gallium phosphide,
  • Example aluminides include, e.g., magnesium aluminide, titanium aluminide, iron aluminide, and nickel aluminide.
  • Example silicides include, e.g., nickel silicide, sodium silicide, magnesium silicide, platinum silicide, titanium silicide, tungsten silicide, and molybdenum silicide.
  • mono-, binary, or ternary, or higher carbides, nitrides, borides, phosphides, aluminides, or silicides that comprise titanium are particularly suitable.
  • titanium sponge is considered a particularly suitable form of titanium metal for use with the disclosed technology. For example, one can contact titanium sponge with a quaternary ammonium salt as described herein so as to give rise to a nanofilamentous (or subnanofilamentous) product, as described herein.
  • Aspect 24 The method of Aspect 23, wherein the conditions comprise a temperature of from 0 to 100 °C, to 200°C, or even to 300 °C for from about 0.5 hours to about 1, 2, 3, 4, or 5 weeks.
  • the temperature can be constant during the time of exposure, but can also be varied, e.g., increased and/or decreased.
  • the temperature can be, e.g., from about 0 to about 300 °C, from about 5 to about 95 °C, from about 10 to about 90 °C, from about 15 to about 85 °C, from about 20 to about 80 °C, from about 25 to about 75 °C, from about 30 to about 70 °C, from about 35 to about 65 °C, from about 40 to about 60 °C, from about 45 to about 55 °C, or even about 50 °C. Temperatures from 100 to 200 °C are also suitable. The temperature can be varied during the exposure (e.g., exposure to a first temperature and then a second temperature), but this is not a requirement.
  • the exposure can be, e.g., according to a preprogrammed schedule that sets temperatures and/or durations of exposure.
  • the exposure temperature can be, e.g., about 25, about 30, about 35, about 40, about 45, about 50, about 55, about 60, about 65, about 70, about 75, about 80, about 90, about 95, or even about 100 °C.
  • the conditions can, in some embodiments, comprise a temperature of from about 20 to about 300 °C and an exposure of from about 0.5 hours to about 2, 3, 4, or even 5 weeks.
  • the conditions can comprise a temperature of about 100 to about 200 °C and an exposure of from about 1 hours to about 1 week.
  • the temperature can be constant during the time of exposure, but can also be varied, e.g., increased and/or decreased.
  • the temperature can be, e.g., from about 100 to about 200 °C, from about 105 to about 195 °C, from about 100 to about 190 °C, from about 115 to about 185 °C, from about 120 to about 180 °C, from about 25 to about 175 °C, from about 130 to about 170 °C, from about 135 to about 165 °C, from about 140 to about 160 °C, from about 145 to about 155 °C, or even about 150 °C.
  • the temperature can be varied during the exposure (e.g., exposure to a first temperature and then a second temperature), but this is not a requirement.
  • the exposure can be, e.g., according to a preprogrammed schedule that sets temperatures and/or durations of exposure.
  • the exposure temperature can be, e.g., about 125, about 130, about 135, about 140, about 145, about 150, about 155, about 160, about 165, about 170, about 175, about 180, about 190, about 195.
  • the method can be performed in a closed system, e.g., in a pressure vessel.
  • the pressure can be atmospheric, but can also be less than atmospheric pressure or even can be greater than atmospheric pressure, e.g., a pressure of greater than 1 atmosphere (101.325 kPa) to about 10 atmospheres (1013.250 kPa).
  • the period of exposure (which can be termed a “reaction time”) can be, e.g., from about 1 hours to about 7 days, from about 5 hours to about 6 days, from about 15 hours to about 5 days, from about 20 hours to about 4 days, from about 24 hours to about 3 days, or even about 2 days.
  • the exposure can be for from 12 hours to about 72 hours, about 15 hours to about 70 hours, about 18 hours to about 64 hours, about 24 hours to about 60 hours, about 30 hours to about 55 hours, about 33 hours to about 52 hours, about 37 hours to about 48 hours, about 40 hours to about 45 hours, and all intermediate values and sub-combinations of ranges.
  • Aspect 25 The method of Aspect 23, comprising contacting a mono-, binary, ternary, or higher boride (which can comprise Ti) with a quaternary ammonium salt and/or base so as to give rise to a product, which product can be nanofilamentous and/or subnanofilamentous.
  • a mono-, binary, ternary, or higher boride which can comprise Ti
  • a quaternary ammonium salt and/or base so as to give rise to a product, which product can be nanofilamentous and/or subnanofilamentous.
  • Aspect 26 The method of Aspect 25, wherein the binary boride comprises one or more titanium borides.
  • Aspect 27 The method of any one of Aspects 23-26, wherein the quaternary ammonium salt and/or base comprises an ammonium hydroxide, an ammonium halide, or any combination thereof.
  • Aspect 28 The method of Aspect 27, wherein the quaternary ammonium hydroxide comprises tetramethyl ammonium hydroxide (TMAOH), tetraethylammonium hydroxide (TEAOH), tetrapropylammonium hydroxide (TPAOH), tetrabutylammonium hydroxide (TBAOH), ammonium hydroxide (NTUOH), their amine derivatives, or any combination thereof.
  • TMAOH tetramethyl ammonium hydroxide
  • TEAOH tetraethylammonium hydroxide
  • TPAOH tetrapropylammonium hydroxide
  • TAAOH tetrabutylammonium hydroxide
  • NTUOH ammonium hydroxide
  • Aspect 29 The method of Aspect 27, wherein the quaternary ammonium salt comprises a quaternary ammonium chloride, a quaternary ammonium bromide, a quaternary ammonium iodide, a quaternary ammonium fluoride, or any combination thereof. It should be understood that one can use either or both of a quaternary ammonium salt and a quaternary ammonium base.
  • Aspect 30 The method of any one of Aspects 23-29, further comprising filtering the product.
  • Aspect 31 The method of any one of Aspects 23-30, further comprising washing the product with a metal salt and/or other water-soluble metal compound.
  • the metal salt can be a metal halide salt, e.g., a Li halide, a Na halide, a K halide, an Rb halide, a Cs halide, a Fr halide, a Be halide, a Mg halide, a Ca halide, a Sr halide, a Ba halide, a Ra halide, a Mn halide, a Fe halide, a Ni halide, a Co halide, a Cu halide, a Zn halide, a Mo halide, aNb halide, a W halide, or any combination thereof.
  • a metal halide salt e.g., a Li halide, a Na halide, a K halide, an Rb halide, a Cs halide, a Fr halide, a Be halide, a Mg halide, a Ca
  • Aspect 32 The method of any one of Aspects 23-31, further comprising washing the product with a metal salt and/or water-soluble metal compounds.
  • the metal salt can optionally comprise metal sulfate, nitrate, chromate, acetate, carbonate, permanganate, or metal hydroxide, or any combination of thereof.
  • Aspect 33 The method of Aspect 32, wherein the metal in the salt can be essentially any metal from the periodic table.
  • the metal in the metal salt can be Li, Na, K, Cs, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Mo, Cd, Ta, or W, or any combination of thereof.
  • a metal salt can be, e.g., LiCl, KC1, NaCl, LiF, KF, NaF, LiOH, KOH, NaOH, or any combination thereof.
  • Aspect 34 The method of any one of Aspects 32-33, wherein the metal salt is LiCl, KC1, NaCl, LiF, CsCl, KF, NaF, LiOH, KOH, NaOH, or any combination thereof.
  • Aspect 35 The method of any one of Aspects 32-33, wherein the metal salt comprises CrCb, MnCh, FeCh, FeCb, CoCh, NiCh, MoCb, FeS04, (NH4)2Fe(S04)2, CuCh, CuCl, ZnCh or any combination thereof.
  • Aspect 36 The method of any one of Aspects 23-35, wherein the product is a composition according to any one of Aspects 1-16.
  • Aspect 37 The method of any one of Aspects 23-36, wherein the nanofilamentous (and/or subnanofilamentous) product exhibits a XRD pattern that, when compared to a XRD pattern of nano- or bulk anatase, exhibit reduced (104) and (105) peaks at around 38° and about 55° two theta (2Q).
  • the disclosed nanofilaments and/or subnanofilaments can, in some embodiments, exhibit a Raman spectrum that is similar to that of bulk anatase, but can differ from bulk anatase in terms of the XRD spectrum, as described herein.
  • a method comprising:
  • the nanoparticulate product optionally at least some nanoparticles having a diameter of from about 2 nm to about 1000 nm, optionally from about 10 to about 100 nm.
  • the nanoparticulate product can be further processed, e.g., by heating, by further reaction, and the like.
  • the further processing can be performed to coarsen the product, e.g., to give rise to larger-size particles, e.g., from about 0.1 to about 0.7 pm, or from about 0.2 to about 0.5 pm.
  • the disclosed methods for making an anatase product of the present disclosure provide a substitute for TiCh (including pigment-grade TiCh) and also provide an improvement over existing processes for making such TiCh, in particular pigment- grade TiCh.
  • the contacting can be at from about 20 to about 80 °C, or from about 25 to about 75 °C, or from about 30 to about 70 °C, or from about 35 to about 65 °C, or from about 40 to about 60 °C, or from about 45 to about 55 °C, even about 50 °C.
  • the contacting can be from , e.g., about 5 minutes to about 5 hours, from about 10 minutes to about 4.5 hours, from about 15 minutes to about 4 hours, from about 20 minutes to about 3.5 hours, from about 30 minutes to about 3 hours, from about 45 minutes to about 2 hours, or any combination or subrange thereof.
  • Aspect 39 The method of Aspect 38, wherein the quaternary ammonium salt and/or base comprises an ammonium hydroxide, an ammonium halide, or any combination thereof.
  • Aspect 40 The method of Aspect 38, wherein the quaternary ammonium base comprises tetramethylammonium hydroxide (TMAOH), tetraethylammonium hydroxide (TEAOH), tetrapropylammonium hydroxide (TPAOH), tetrabutylammonium hydroxide (TBAOH), ammonium hydroxide (NH4OH), their amine derivatives, or any combination thereof.
  • TMAOH tetramethylammonium hydroxide
  • TEAOH tetraethylammonium hydroxide
  • TPAOH tetrapropylammonium hydroxide
  • TSAOH tetrabutylammonium hydroxide
  • NH4OH ammonium hydroxide
  • Aspect 41 The method of Aspect 38, wherein the quaternary ammonium salt comprises a quaternary ammonium chloride, a quaternary ammonium bromide, a quaternary ammonium iodide, a quaternary ammonium fluoride, or any combination thereof. As described elsewhere herein, one can use either or both of a quaternary ammonium salt and a quaternary ammonium base.
  • Aspect 42 The method of any one of Aspects 38-41, further comprising filtering the product.
  • a composition comprising a population of anatase nanoparticles made according to any one of Aspects 38-42.
  • Such nanoparticles can be in the size range of from about 200 nm to about 600 nm, e.g., from about 200 nm to about 600 nm, from about 225 to about 575 nm, from about 250 to about 550 nm, from about 275 nm to about 525 nm, from about 300 to about 500 nm, from about 325 to about 475 nm, from about 350 to about 450 nm, from about 375 to about 425 nm, or even about 400 nm.
  • Aspect 44 A method, comprising replacing T1O2 with a population of anatase nanoparticles made according to any one of Aspects 38-42.
  • a pigment normally made with traditional T1O2 by replacing the traditional T1O2 with anatase nanoparticles according to the present disclosure, e.g., according to any one of Aspects 38-42.
  • a method comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non- water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting optionally performed while shaking, and the contacting being performed under conditions sufficient to give rise to mesoporous particles.
  • a method comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non- water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting optionally performed while shaking, the contacting being followed by washing with at least one salt and performed under conditions sufficient to give rise to mesoporous particles.
  • a method comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non- water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting performed while shaking and at a temperature of from about 50 to about 95 °C, followed by washing with LiCl to give rise to mesoporous particles.
  • Aspect 48 A composition comprising mesoporous particles made according to any one of claims 45-47.
  • the mesoporous particles can exhibit a XRD pattern that, when compared to a XRD pattern of nano- or bulk anatase, exhibit reduced (104) and (105) peaks at around 38° and about 55° two theta (2Q).
  • the disclosed mesoporous particles can, in some embodiments, exhibit a Raman spectrum that is quite similar to that of bulk anatase, but can also differ from bulk anatase in terms of the XRD spectrum, as described herein. [00281] Aspect 49.
  • a composition comprising mesoporous particles, wherein the mesoporous particles comprise titanium and wherein the mesoporous particles exhibit a XRD pattern that, when compared to a XRD pattern of nano- or bulk anatase, exhibit reduced (104) and (105) peaks at around 38° and about 55° two theta (2Q).
  • the disclosed mesoporous particles can, in some embodiments, exhibit a Raman spectrum that is quite similar to that of bulk anatase, but can also differ from bulk anatase in terms of the XRD spectrum, as described herein.
  • Aspect 50 The composition according to any one of claims 48-49, further comprising a therapeutic.
  • a method comprising effecting delivery of a therapeutic to a subject, the therapeutic being comprised in a composition according to any one of claims 48-49.
  • Aspect 52 An electrode, the electrode comprising a composition according to any one of claims 48-49.
  • a device comprising a composition according to any one of claims 48-49.
  • Aspect 54 The device of claim 52, wherein the device is an energy storage device.
  • Aspect 55 A method, the method comprising operating the device of any one of claims 52-53.

Landscapes

  • Health & Medical Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Pharmacology & Pharmacy (AREA)
  • Epidemiology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Inorganic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Oxygen, Ozone, And Oxides In General (AREA)
  • Carbon And Carbon Compounds (AREA)

Abstract

Provided are methods to convert - through a bottom-up approach – binary and ternary titanium carbides, nitrides, borides, phosphides, aluminides, and silicides into nanofilaments that in some cases self-assemble into 2D flakes by immersing them in a quaternary ammonium solution at moderate temperatures. The resulting flakes can be C-containing anatase-based layers that are in turn comprised of nanofilaments in cross-section, some of which nanofilaments can be few microns long in some instances. Electrodes made from these materials performed well in energy systems. The materials also reduce the viability of some cancer cells. Also provided are mesoporous materials, devices, and related methods.

Description

BOTTOM-UP SCALABLE SYNTHESIS OF OXIDE-BASED SUB-NANO AND
NANOFILAMENTS AND NANOFILAMENT-BASED TWO-DIMENSIONAL FLAKES AND MESOPOROUS POWDERS
RELATED APPLICATIONS
[0001] The present application claims priority to and the benefit of United States patent application no. 63/148,348 (filed February 11, 2021); United States patent application no. 63/167,197 (filed March 29, 2021); United States patent application no. 63/171,293 (filed April 6, 2021); and United States patent application no. 63/275,631 (filed November 4, 2021). The foregoing applications are incorporated herein in their entireties for any and all purposes.
TECHNICAL FIELD
[0002] The present disclosure relates to the field of ID and 2D materials and to the field of metal oxide-based nanomaterials.
BACKGROUND
[0003] One (ID) and two-dimensional (2D) materials offer advantages that their 3D counterparts do not. Historically, the starting point to synthesis of 2D materials in bulk has mostly been layered solids, such as clays, graphite or, more recently, MAX phases.
The idea that one can synthesize 2D solids in bulk, from non-lay ered solids was deemed to be difficult/impossible. Accordingly, there is a need for 2D solids, especially for such solids synthesized in bulk from non-lay ered solids. Most ID nanofilaments are not stable in water. Accordingly, there is a need for ID solids, in particular such solids that are water stable.
SUMMARY
[0004] As an illustration of the disclosed technology, we convert - through a bottom-up approach - 10 example binary and ternary titanium carbides, nitrides, borides, phosphides, and silicides into 2D flakes by immersing them in a tetramethylammonium hydroxide (TMAH) solution at temperatures in, e.g., the 25 to 85 °C range. Based on X- ray diffraction, density functional theory, X-ray photoelectron, electron energy loss, Raman, X-ray absorption near edge structure spectroscopies, transmission and scanning electron microscope images and selected area diffraction, we conclude that the resulting flakes are C-containing anatase-based layers that are in turn comprised of ~ 6 xlO A2 nanofilaments (in some embodiments) in cross-section some of which are few microns long. Electrodes made from some of these films performed well in lithium-ion and lithium-sulphur systems. These materials also reduce the viability of cancer cells thus showing potential in biomedical applications. Synthesizing two-dimensional (2D) materials that are in turn comprised of ID entities, at near ambient conditions, with non- lay ered, inexpensive, precursors (e.g., TiC, T1B2, TiN, and the like) is paradigm-shifting and will undoubtedly open new and exciting avenues of research and applications.
[0005] In meeting the described long-felt needs, the present disclosure provides a composition, comprising: a plurality of metal oxide (e.g., metal oxide-based) nanofilaments and/or subnanofilaments, and optionally an amount of carbon. (As described herein, the nanofilaments can comprise titanium.) Example such compositions are found in “Bottom-up, scalable synthesis of anatase nanofilament-based two- dimensional titanium carbo-oxide flakes”, Badr et ak, Materials Today (2021), the entirety of which is incorporated herein by reference for any and all purposes.
[0006] Also provided is a device, the device comprising a composition according to the present disclosure, e.g., according to any one of Aspects 1-16.
[0007] Additionally disclosed are methods, comprising operating a device according to the present disclosure, e.g., a device according to Aspect 16.
[0008] Also provided are methods, comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non-water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting being performed under conditions sufficient to give rise to a nanofilamentous product. [0009] Also disclosed are methods, comprising contacting particulate TiCh with a quaternary ammonium salt, the contacting being performed under conditions sufficient to give rise to an anatase nanoparticulate product, the nanoparticulate product optionally at least some nanoparticles having a diameter of from about 2 nm to about 1000 nm, optionally from about 10 to about 100 nm.
[0010] Further provided are compositions, comprising a population of anatase nanoparticles made according to the present disclosure, e.g., according to one of Aspects 38-42.
[0011] Also disclosed are methods, comprising replacing TiCh with a population of anatase nanoparticles made according to the present disclosure, e.g., according to any one of Aspects 38-42.
[0012] Also provided is a method, comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non-water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting optionally performed while shaking, and the contacting being performed under conditions sufficient to give rise to mesoporous particles.
[0013] Also disclosed is a method, comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non-water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting optionally performed while shaking, the contacting being followed by washing with at least one salt and performed under conditions sufficient to give rise to mesoporous particles.
[0014] Further provided is a method, comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non-water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting performed while shaking and at a temperature of from about 50 to about 95 °C, followed by washing with LiCl to give rise to mesoporous particles.
[0015] Also provided are mesoporous particles made according to the present disclosure, e.g., according to any one of Aspects 45-47.
[0016] Further provided is a composition, comprising mesoporous particles, wherein the mesoporous particles comprise titanium and wherein the mesoporous particles exhibit a XRD pattern that, when compared to a XRD pattern of nano- or bulk anatase, exhibit reduced (104) and (105) peaks at around 38° and about 55° two theta (2Q).
[0017] Also provided is a method, comprising effecting delivery of a therapeutic to a subject, the therapeutic comprising in a composition according to the present disclosure, e.g., according to any one of Aspects 48-49.
[0018] Also disclosed is a method, comprising effecting delivery of a therapeutic to a subject, the therapeutic comprising in a composition according to the present disclosure, e.g., according to any one of Aspects 48-49.
[0019] Further provided is an electrode, the electrode comprising a composition according to the present disclosure, e.g., according to any one of Aspects 48-49.
[0020] Also disclosed is a device, the device comprising a composition according to the present disclosure, e.g., according to any one of Aspects 48-49.
[0021] Also provided is a method, the method comprising operating a device according to the present disclosure, e.g., according to of any one of Aspects 52-53.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The file of this patent or application contains at least one drawing/photograph executed in color. Copies of this patent or patent application publication with color drawing(s)/photograph(s) will be provided by the Office upon request and payment of the necessary fee. [0023] In the drawings, which are not necessarily drawn to scale, like numerals can describe similar components in different views. Like numerals having different letter suffixes can represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various aspects discussed in the present document. In the drawings:
[0024] Figs. 1A-1D. Fabrication process, scanning electron microscope (SEM) micrographs and Density functional theory (DFT) structures. (FIG. 1A) Schematic of fabrication process, (FIG. IB) Typical cross-sectional SEM micrograph of a TiC-derived filtered film (FF). Note undigested TiC particles in bottom right comer. Inset shows pictures of typical colloidal suspension. (FIG. 1C) Isometric side view of 4 Ti-layered 2D anatase-based structure with TbCLC chemistry that best fits XRD and selected area diffraction (SAD) results. Blue, orange, red, and black spheres represent Ti, 2- and 3-fold coordinated O, and C respectively. Vertical arrow on left denotes approximate dimension; (FIG. ID) Top view of nanofilaments (nfs) growing in [200] (top) and [110] (bottom) directions. Inset in (FIG. ID) compares experimental LPs (dashed lines) with DFT predictions (solid lines) as a function of number of Ti layers. Our coordinate system is shown in lower left in c and d and is not that of bulk anatase.
[0025] Figs. 2A-2D. Characterization of 2D material. (FIG. 2A) XRD patterns, on log scale, of filtered, vertically oriented, TbAlC2-derived film in transmission mode. Inset shows pattern of horizontally oriented film. 5° 2Q peak is due to Kapton tape. Blue squares are 2Q locations determined from TEM-SAD patterns (Table 3). (FIG. 2B) Raman spectrum of FF obtained from precursors indicated. All powders heated at 50 °C for 3 d and washed with ethanol and water, except the top T1B2 one that treated at 80°C for 2d. All peaks belong to anatase. [15] (FIG. 2C) Core loss electron energy loss spectroscopy (EELS) data measured from 5 individual particles. Graph shows carbon -K edge at -280 eV energy loss, titanium -L3,2 peaks at -450 eV energy loss and oxygen -K edge at -530 eV energy loss. All spectra are normalized to the Ti edge peak intensity and are vertically separated for clarity. (FIG. 2D) XANES results of TiC-derived films together with those for anatase, T13AIC2, TiC and T1CI3. Both TiC samples were reacted in TMAH at 50°C for 3d. Inset shows X-ray Absorption Near Edge Structure (XANES) derivative. [0026] Fig. 3A-3D. Titanium carbo-oxide (TCO) Flake morphology. (FIG. 3A) Typical transmission electron microscope (TEM) image of TCO flake > 4 pm in lateral size. SAD of area encircled in red is shown in top right inset. Two arcs indicate fiber texture along [110] and [200] directions. Bottom inset is a higher magnification of top left comer showing frayed nanofilaments in a direction that is in accordance with the arcs. (FIG. 3B) Scanning transmission electron microscope (STEM) showing individual filaments, the width of which is ~ 10 A. Bottom inset shows nanofilaments being chemically "drawn out" from a large central T13AIC2 particle. (FIG. 3C) Atomic force microscope (AFM) of TCO self-assembled nanofilaments derived from TiC heated in TMAH at 80°C for 3d and washed with water. (FIG. 3D) Same as (FIG. 3C) but after diluting the colloidal suspension 500X and drop cast on glass slide. Inset shows height profile corresponding to blue line in (FIG. 3D); thinnest filaments are « 1.5 nm high.
[0027] Figs. 4A-4D. (FIG. 4A) Tauc plots of various precursor-derived films. Dashed lines model baseline due to Urbach tail absorption; solid lines are fits to linear parts. Charge-discharge curves of, (FIG. 4B) Voltage profile for Ti3AlC2-derived electrode material when tested in lithium-ion batteries (LIBs) at 20 mAg 1; inset shows cyclic voltammogram at 0.1 mV s 1, (FIG. 4C) Charge-discharge curves of TCO cathode at various current rates in lithium-sulfur (Li-S) cell. (FIG. 4D) Cancer cell (see text) viability. Values indicate mean ± SD (n = 3); *p < 0.05.
[0028] Figs. 5A-5F. SEM micrographs of FFs’ cross sections after ethanol and LiCl washing made starting with, (FIG. 5A) Ti3SiC2, (FIG. 5B) T13AIC2, (FIG. 5C)
TriSbP, (FIG. 5D) TiN, (FIG. 5E) T1B2, and (FIG. 5F) TriSri. Insets show corresponding colloidal suspensions and FFs.
[0029] Figs. 6A-6C. X-ray diffractograms (shifted vertically for clarity) of FF from (FIG. 6A) Parent TiC, T13AIC2, TriSiC2 precursors (black lines), and their derived 2D TCO films (red, blue, and green curves, respectively) after washing with ethanol and without sonication. (FIG. 6B) TiC (red, bottom), T13AIC2 (blue, middle), and TriSiC2 (green, top) derived films after washing with ethanol then LiCl solution. (FIG. 6C) T1B2 (red, bottom), TiN (blue, middle), and TriSri (green, top), derived films after washing with ethanol then LiCl solution. [0030] Figs. 7A-7B. (FIG. 7A) Setup used to obtain XRD patterns from vertically oriented films in transmission mode. Inset shows Kapton tape with drop cast film taped to vertical aluminum sample holder. (FIG. 7B) XRD patterns (shifted vertically for clarity) of vertically aligned ethanol washed FF, derived from precursors indicated.
Also shown is pattern of Kapton tape. Asterisks denote peaks belonging to unreacted precursors. In all but one case, precursors were heated in TMAH solution at 50°C for 3d as described in the materials and methods section. In one case, the TiC powders were immersed in the TMAH at 50°C for lid (blue, top). For XRD characterization, 1-1.5 ml of colloidal suspension was drop cast on Kapton tape using a pipette then air dried. Black vertical line at 5° originated from the Kapton tape. Blue lines are guides to the eye to the anatase-based 2D structure.
[0031] Figs. 8A-8F. Typical TEM images of (FIG. 8A) and (FIG. 8B) TiC- derived flakes (50 °C, 3d) (FIG. 8C) Same as (FIG. 8A) but TiC was heated to 80°C for 3d emphasizing the fibrous nature of our TCO flakes. (FIG. 8D) nanofilaments crystallizing from an amorphous TCO background. Inset reveals high resolution image of crystalline nanofilaments 2-3 nm wide and few microns long. In the previous cases, reaction products were water washed. (FIG. 8E) Ti3SiC2-derived flakes (50°C for 3d, washed with ethanol) captured from crushed FF. (FIG. 8F) Nanofilaments appearing to be chemically “drawn” from T13AIC2 phase (dark particle in center) (50°C, 3d; washed with ethanol and water). Insets show SAD pattern from area bounded by red circles. Inset in f show both faint rings (from TCO) and MAX phase spots.
[0032] Figs. 9A-9B. (FIG. 9A) TEM and (FIG. 9B) AFM micrographs of TiC- derived material (80°C for 5d and water washed). AFM samples were spin-coated on glass slides from initial suspension after dilution.
[0033] Figs. 10A-10B. (FIG. 10A) 6-layered anatase structure. Slab thickness is ~ 8 A. (FIG. 10B) Phonon density of states of 4-layered structure shown in Fig. lc.
[0034] Fig. 11. Post LiCl-washed XPS spectra of Ti 2p region (1st column), C Is region (2nd column), O Is region (3rd column) and Fermi edge (4th column) obtained from TiC- (1st row, top) , T13AIC2- (2nd row), Ti3SiC2- (3rd row), TiN- (4th row), T1B2- (5th row), and TiCh-based (6th row) films. Peak fits and results are summarized in Tables 4 and 7. Dashed vertical lines are guides to the eye. [0035] Figs. 12A-12B. XPS spectra as a function of processing in Ti 2p region (1st column), C Is region (second column), O Is region (third column), and Fermi edge (last column) of, (FIG. 12A) T13AIC2 -based and, (FIG. 12B) TriSiC2 -based filtered films. Dashed vertical lines are guides to the eye. Notably positions of Ti peaks appear to be insensitive to solution used to wash the films and even after heating to 800 °C in Ar in the T13AIC2 case (compare top spectra in blue to those below them in a).
[0036] Figs. 13A-13E. XPS spectra of TCO FF for (FIG. 13A) N Is and, (FIG. 13B) Cl 2p regions derived from TiC (black, bottom), T13AIC2 (red, second from bottom) Ti3SiC2(blue, third from bottom), TiN (green, third from top), T1B2 (purple, second from top) and T1O2 (yellow, top) powders, (FIG. 13C) Si 2p spectra the Ti3SiC2-derived FF, (FIG. 13D) A12p spectra for Ti3AlC2-derived FF, (FIG. 13E) B is spectra for T1B2- derived FF. All samples were washed with ethanol and LiCl before filtration, followed by vacuum drying before XPS analysis.
[0037] Figs. 14A-14B. Thermogravimetric plots for, (FIG. 14A) All samples, ramped at 10 °C/min to 800 °C in Ar. Sample labeled ethanol was washed with ethanol; those labeled LiCl were first washed with ethanol and then with a LiCl solution. (FIG.
14B) TiC-derived film heated in air to 800 °C; c) Mass spectrometry results for b. Up to ~ 400 °C, most of gas released is water. After 400 °C, CO2 is released. Dashed black vertical line is a guide to the eye.
[0038] Fig. 15. Rietveld analysis of XRD diffractograms of LiCl washed filtered films heated to 800 °C in Ar. The c2 values are listed on figures. Results are summarized in Table 8. Purple lines are differences between fits in red and experimental results in black.
[0039] Figs. 16A-16B. (FIG. 16A) XRD diffraction patterns of TiCh-derived material heated in TMAH for times and temperatures indicated on figure. In the 2D anatase the (104 and (105) peaks are absent and the 63° peak is shifted towards 60°. (FIG. 16B) TEM of anatase nanoparticles in the range of 20 nm. Insets show high magnification image and SAD pattern of the obtained T1O2 nanoparticles.
[0040] Figs. 17A-17D. Electrochemical performance of Ti3AlC2-based TCO as electrode materials in Li-ion battery. (FIG. 17A) Electrochemical impedance spectroscopy Nyquist plot at open circuit potential, (FIG. 17B) specific capacity vs. cycle number and specific currents indicated. (FIG.17C) Voltage profile at specific current of 100 mA g 1. (FIG. 17D) Specific capacity and Coulombic efficiency vs. cycle number for cell shown in c.
[0041] Figs. 18A-18B. Electrochemical characterization of TiC-based FF electrode in Li-S cell: (FIG. 18A) CV curves, (FIG. 18B) Cycling stability at 0.2 C. S- loading is 0.8 mg. Capacity was, more or less, constant at ~ 1000 mAh/g for about 300 cycles before fading.
[0042] Fig. 19 provides images of exemplary mesoscopic materials according to the present disclosure.
[0043] Table 1 provides sources of example powders and reagents used in this work.
[0044] Table 2 provides a summary of example precursors, TkTMAH mole ratios, and synthesis conditions.
[0045] Table 3 provides a summary of interlayer spacing (d) values and the corresponding diffraction angle (2Q) acquired from XRD pattern shown in Fig. 2a and their comparison to those obtained from 7 different SAD patterns obtained from 5 different samples. All samples derived from parent TiC heated at 50°C then washed with ethanol and water.
[0046] Table 4 provides a summary of fitting of XPS results shown in Fig. 11.
[0047] Table 5 provides chemistries of 5 different flakes deduced from EELS measurements shown in Fig. 2c. Last row suggests possible chemistries where X sum of O, C and N. Flakes were prepared by dry rubbing filtered films made by heating TiC powders in TMAH for 3d at 50°C, then washed with ethanol.
[0048] Table 6 provides chemistries of number of flakes from different precursors deduced from EDS measurements. Last row suggests possible Ti:0 ratios of these samples. SEM-EDS measurements were obtained from cross-sections of filtered films made of the precursor T13AIC2, Ti3SiC2, Ti3GaC2 powders reacted with TMAH at 50°C for 72h and washed with ethanol then a LiCl solution. TEM-EDS measurements were conducted on samples prepared by dry rubbing Ti3SiC2- and TiB2-derived filtered films made by reacting the powder with TMAH at 50°C for 72h and washing with ethanol. [0049] Table 7 provides Ti:0 chemistries obtained from the Ti area under ~ 459 eV peak and O under ~ 530 eV peak shown in Fig. 11.
[0050] Table 8 provides a summary of Rietveld analyses of filtered films after heating in Ar to 800°C. Corresponding XRD patterns are plotted in Fig. 15.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0051] The present disclosure may be understood more readily by reference to the following detailed description of desired embodiments and the examples included therein.
[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will control. Preferred methods and materials are described below, although methods and materials similar or equivalent to those described herein can be used in practice or testing. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.
[0053] The singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.
[0054] As used in the specification and in the claims, the term "comprising" can include the embodiments "consisting of and "consisting essentially of.” The terms “comprise(s),” “include(s),” “having,” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that require the presence of the named ingredients/steps and permit the presence of other ingredients/steps. However, such description should be construed as also describing compositions or processes as "consisting of and "consisting essentially of the enumerated ingredients/steps, which allows the presence of only the named ingredients/steps, along with any impurities that might result therefrom, and excludes other ingredients/steps.
[0055] As used herein, the terms “about” and “at or about” mean that the amount or value in question can be the value designated some other value approximately or about the same. It is generally understood, as used herein, that it is the nominal value indicated ±10% variation unless otherwise indicated or inferred. The term is intended to convey that similar values promote equivalent results or effects recited in the claims. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but can be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. In general, an amount, size, formulation, parameter or other quantity or characteristic is “about” or “approximate” whether or not expressly stated to be such. It is understood that where “about” is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise.
[0056] Unless indicated to the contrary, the numerical values should be understood to include numerical values which are the same when reduced to the same number of significant figures and numerical values which differ from the stated value by less than the experimental error of conventional measurement technique of the type described in the present application to determine the value.
[0057] All ranges disclosed herein are inclusive of the recited endpoint and independently of the endpoints (e.g., "between 2 grams and 10 grams, and all the intermediate values includes 2 grams, 10 grams, and all intermediate values"). The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value; they are sufficiently imprecise to include values approximating these ranges and/or values. All ranges are combinable.
[0058] As used herein, approximating language can be applied to modify any quantitative representation that can vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about” and “substantially,” may not be limited to the precise value specified, in some cases. In at least some instances, the approximating language can correspond to the precision of an instrument for measuring the value. The modifier “about” should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4.” The term “about” can refer to plus or minus 10% of the indicated number. For example, “about 10%” can indicate a range of 9% to 11%, and “about 1” can mean from 0.9- 1.1. Other meanings of “about” can be apparent from the context, such as rounding off, so, for example “about 1” can also mean from 0.5 to 1.4. Further, the term “comprising” should be understood as having its open-ended meaning of “including,” but the term also includes the closed meaning of the term “consisting.” For example, a composition that comprises components A and B can be a composition that includes A, B, and other components, but can also be a composition made of A and B only. Any documents cited herein are incorporated by reference in their entireties for any and all purposes.
[0059] In all cases, except when TiC was the precursor, 2D flakes were obtained. A typical cross-sectional scanning electron microscope (SEM) image of a TiC- derived film (Fig. lb) clearly showed the 2D nature of the FFs. This micrograph is especially revealing in that it shows both undigested TiC particles (bottom right) and flakes. A colloidal suspension, with concentrations in the 10 g/L range, is shown in inset in Fig. lb. SEM images of other films are shown in Fig. 5. The FFs varied in color from light to dark gray. The fact that these flakes can be synthesized from non-layered precursors and result in FF that are structurally and chemically similar is strong evidence for a bottom-up approach. In our interpretation, TMAH acts as a near-universal solvent that dissolves the precursor and releases Ti atoms that spontaneously react with C and O in the TMAH/water to form 2D flakes comprised of self-assembled nanofilaments (see below). The TMAH role is thus twofold: solvent and templating agent.
[0060] A X-ray diffraction (XRD) pattern of a Ti3AlC2-derived film after ethanol washing (inset in Fig. 2a) is typical of 2D materials. [7, 9] XRD patterns of dry FF obtained from other precursors are shown in Fig. 6. The absence, for the most part, of peaks associated with the precursors is noteworthy. To gain insight into the underlying structure we obtained XRD patterns (Fig. 2a) on a vertically oriented FF [14] (see Fig. 7a) that was obtained after heating T13AIC2 for 3 days at 50 °C then washed with ethanol and water. The red vertical lines were obtained as follows: First, the c-lattice parameter, LP, was calculated from horizontally oriented film (inset in Fig. 2a). The structure shown in Fig. lc was then used to calculate the position of all peaks. All planes with non-zero t indices were eliminated, leaving the red lines. The good agreement between the density functional theory (DFT) generated LPs and the experimental ones (inset in Fig. Id) lends credence that we are dealing with a 4 Ti-layered anatase-based 2D material (see below). Patterns for other vertically oriented films, derived from other precursors, are shown in Fig. 7b. In all cases, peaks - with identical angles - were obtained. This is crucial and cannot be overemphasized since it demonstrates that precursor chemistry does not alter the structures formed, including their LPs.
[0061] Transmission electron microscope (TEM) images of TiC-, TriSiC2-, and Ti3AlC2-derived flakes revealed the presence of 2D flakes > 1 pm in lateral sizes (Fig. 3a; Fig. 8). Selected area diffraction, SAD, of the latter in some regions resulted in 3 main rings (see insets in Figs. 8b and c). When the ring d-spacings were converted to 2Q values (blue squares in Fig. 2a) good agreement with the XRD peaks was found confirming our SAD patterns are representative (For more results see Table 3). More interestingly, in other regions, two sets of arcs (insets in Fig. 3a and Fig. 8a) were observed. One set of arcs indicated that the long axis of the nanofilaments is in the [110] direction; the other in the [200] direction. The angle between them is shown in both inset and main micrograph. They are in the same directions as the frayed fibers seen at the sheet edges in top left.
Note that the locations where arcs were observed were limited. The regions where three rings were observed were much more ubiquitous, which implies the presence of smaller nfs that are pointing in all directions. Along the same lines, the presence of truly amorphous regions cannot be discounted at this stage.
[0062] The scanning transmission electron microscope (STEM) micrograph (Fig. 3b) clearly shows the fibrous nature of the sample. The width of individual nanofilaments is estimated to be ~ 1 nm. Since their thickness is ~ 5.9 A, it follows that we are dealing with nanofilaments roughly 6 xlO A2 in cross-section that can be micrometers long (see inset in Fig 3b and Fig. 8c). Other TEM micrographs are shown in Fig. 8. We note in passing theoretical surface area of these nanofilaments is ~ 1500 m2/g.
[0063] Figure 3c and Figure 9 show TEM and atomic force microscope (AFM) maps of a TiC-derived sample (5d at 80°C, water washed), spin coated on glass. The fibrous nature of the product and its tendency for self-alignment are obvious. When the same suspension was diluted 500X and drop cast individual nanofilaments separated (Fig. 3d). An AFM trace along the blue line in Fig. 3d shows that the thicknesses, or heights, of the smallest ribbons were « 1.5 nm (inset in Fig. 3d). [0064] To determine the number of Ti-layers per filament, we used first- principles calculations to predict the LPs. For this, relaxations were performed for three supercell structures consisting of 2- (not shown), 4- (Fig. lc), and 6-Ti (Fig. 10a) layers, with the lowest energy anatase (101) surfaces [16] bounding the top and bottom. (Note our coordinate system is different than anatase's; here the c-axis is the stacking direction. See crystallography section in SM). We then replaced every 2 O atoms by a C atom in the slab centers for an overall chemistry of Ti02-2xCx where x is 0.25 or TUtUC. This was done to account for structural C and render the structure dynamically stable (Fig. 10b). All other configurations resulted in dynamic instabilities. As shown in inset in Fig. Id, the LPs of the b axes of the three structures are in good agreement with experimental values especially given that the DFT calculations were performed at 0 K. However, a large increase in the a-LP is observed - that is closer to the experimental values - when the number of Ti layers increases to 4 or 6 (blue curves in inset in Fig. Id). The thicknesses of the 4- and 6-layered anatase are - 5.9 A and ~ 8 A. respectively. The diameter of a TMA cation ranges from 4.5-6 A [17, 18] Using the low end, the ri-spacing between filaments for the 4- and 6-layered structures would be 10.4 A and 12.5 A, respectively. Using the high end, results in a d-spacing (11.9 A) for the 4-layered structure that agrees quite well with the 11.5 d-spacing obtained from XRD (inset in Fig. 2a and Fig. 6a). Said otherwise, the experimental value is consistent with a 4-layered structure; the 6-layered one is too thick.
[0065] Raman spectroscopy of a number of FFs (Fig. 2b) show that all peaks belong to anatase regardless of precursor chemistry. [15, 19]
[0066] To elucidate the flakes' chemistry a comprehensive X-ray photoelectron spectroscopic (XPS) study (Figs. 11- 13 and Table 4) was carried out. The Ti, O binding energies were found to be weak functions of precursor chemistry (Fig. 11), washing protocol, or even heating to 800 °C in Ar (Fig. 12a). This confirms once again the chemical similarities of all films. Further evidence for a bottom-up approach is that - except for Ti3SiC2-derived films, that show a small Si peak - all others XPS spectra were comprised of only three elements - Ti, C and O - regardless of starting precursor (Fig. 13).
[0067] As discussed, it was not possible to quantify the C-content in our flakes. EELS, of several TiC-based flakes indicated aTi:C:0 atomic ratio of - 1:1:1 (Fig. 2c and Table 5). The flakes incorporated small amounts of N that are ignored going forward for simplicity. It is crucial to note here that both EDS in the SEM and TEM confirmed a Ti:0 ratio of - 1.0 (Table 6). Based on this ratio, and if no C were in the structure, the Ti- oxidation state would have to be - +2, which is belied by X-ray absorption near edge structure (XANES) measurements (Fig. 2d) at the Ti K-edge on TiC-derived films that indicate that the average oxidation state, AOS, is between +3 and +4. In all cases the 0:Ti ratio in XPS was closer to 3 than 1 (Table 7).
[0068] To better understand the chemistry and we carried morphology of our flakes out a thermogravimetric analysis, TGA, in Ar up to 800 °C on select films. The results are shown in Fig. 14a. With the notable exception of the Ti02-derived films, in all other cases there were two major weight loss events when LiCl washed films were heated. One before - 200 °C and another at - 300 °C or higher temperatures. For the T1B2, TiC and Ti3SiC2-derived films, the latter is quite sharp. In most cases the weight loss at - 300 °C was about 4%. The weight losses at > 300 °C for the T13AIC2- and TiN-derived films are more diffuse, but the total was still - 4 %. The sharpness of the weight loss event at 300 °C is better seen in Fig. 14b, for a TiC-film heated in air to 800 °C. In that run, the TGA was equipped with a mass-spectrometer, the results of which shown in Fig. 14c. It follows that the only gas released up to 400 °C is water. The first is most probably weakly bound interlayer water; the second can be water of hydration associated with the Li ions. The lack of higher atomic number species indirectly attests to the fact that the LiCl washing step rids the interlayer space of TMA cations and other reaction products. Not surprisingly the weight losses of films washed with only ethanol were higher (red curve in Fig. 14a).
[0069] After the TGA runs, we obtained XRD patterns of the resulting powders (Fig. 15). Rietveld analysis of the XRD pattern resulted in the values listed Table 8. In all cases, two major phases were identified: a Li-titanate, LT, phase - Li1.33Ti1.67O4 - and rutile or anatase. In the case of T13AIC2, Ti3SiC2, TiC the molar ratio of the T1O2/LTA was - 7:3; for T1B2 the ratio was closer to 1:1; for T1O2 there is little LT. Note that the higher the Li content the higher the Ti3+ fraction in the films. Our approach can thus be used to tune the Ti3+/Ti4+ ratio, a consideration in many applications. [0070] Washing with ethanol alone and heating the films in Ar to 800 °C, no Li- containing phases are obtained. The presence of a LT phase thus implies that cations (TMA+ and/or protons) between the layers are exchanged by Li during the LiCl washing step in a fashion quite reminiscent of our MXene work.[20, 21] The TiCh-derived samples were only lightly lithiated, even after washing with LiCl (Table 8), because in this case the material is not layered (see Fig. 16). This sample's TGA (black curve in Fig. 14a) is an outlier for the same reason. Cationic exchange eliminates the possibility we are dealing with layered double hydroxides. The absence of a Cl signal in XPS (see Fig. 13b) also supports this conclusion.
[0071] Based on the EELS, XANES, DFT and TGA results it is reasonable to assume that the chemistry of flakes is given by Zd(Tί4+)i-d(Tί3+)d Ch-2xCx, with x < 1.0. Z is a cation that accounts for the fact that the Ti-oxidation state is < 4+. Said otherwise, the decrease in oxidation state must be balanced by cations. Note this conclusion is predicated on the nanofilaments having no defects, a very unlikely scenario. The fact that many of the films are dark gray to black strongly suggest the presence of defect states in the band gap.
[0072] The overall situation is even more complex. For example, in some regions, the Ti:X ratio, where X = O + C+ N approaches 1 (see spots 1 and 5 in Table 5).
It is hereby acknowledged that what we are dealing with is a quite complex system that is not necessarily homogenous and will require much work to decipher. These comments notwithstanding, our conclusions concerning the structure of the flakes and the presence of C in the structure remain valid.
[0073] Before discussing properties, it is useful to discuss the mechanisms involved in the formation of the nanofilaments and 2D layers. Chen et al. - starting with tetra-n-butyl titanate and TMAH - concluded that the presence of TMAH provides an organic cation to assist and direct the Ti-octahedra poly condensation process that resulted in the regular arrangement of rectangle nanocrystalline anatase particles they observed.[15] Tan et al. treated TiCL hydrothermally at 125 °C as a function of time.[19] After 1 and 4 h reaction times, their XRD patterns are - but for the location of the (240) near 60° 2Q - identical to Fig. 2a. When they increased their reaction times to 12 h and 24 h, their 2D material converted to bulk anatase. They proposed a model where the TMAH helps in assembling the Ti octahedra into 2D layers, while simultaneously intercalating the resultant sheets. There is no reason to believe that this mechanism does not apply here as well, except that because we are working at temperatures low enough that the TMA molecules are more stable, [22] our material does not transform to bulk anatase. Lastly, in contradistinction to all previous work, herein the TMAH not only caps the low energy ( OOi) planes, [19] but must also cap a second surface perpendicular to the growth direction. This creates a situation where growth is confined to one dimension. Inset in Fig. 3b and Fig. 8f suggest that the filaments are chemically "drawn" out of the precursor and the poly condensation process may (without being bound to any particular theory) occurs at that interface. Once the nanofilaments are formed they must self-assemble into 2D flakes. Fig. 8d is a snapshot of how, in certain regions, the nanofilaments self-align to form "crystalline" regions.
[0074] Films derived from TiC and the MAX phases were conductive, with conductivities in the range of 0.01 to 0.05 S/cm; those made with T1O2 and T1B2 are not. These conductivities are roughly 5 to 6 orders of magnitude lower than MXenes, that range from 2,000 to 25,000 S/cm, but notably orders of magnitude higher than typical oxides, especially the more common version of layered titanates, viz. lepidocrocites.[23- 25] The conductivity is not always present and suggests an unknown variable is at play that is currently being investigated.
[0075] To shed light on the electronic structure, we measured their UV-vis optical absorption spectra from 200 nm to 800 nm. Tauc plots (Fig. 4a) of all films show a clear signature of an indirect band gap, Eg, as well as a pronounced Urbach tail due to transitions between sub-gap states. When a modified Tauc method was used to deconvolve the inter-band transitions from the contributions of disorder-related Urbach tail states, [26] we concluded that the indirect band gaps fall in the 4 eV range. These values are the highest ever reported for anatase but consistent with increases in Eg as dimensions shrink. [27] Liao et al. [28] predicted and confirmed, Eg ~ 3.6 eV for their 2-Ti layered 2D anatase flakes. Our E is even higher because our flakes are comprised of ~ 6 xlO A2 nanofilaments. This record Eg value for T1O2 cannot be overemphasized since it indirectly confirms the extreme dimensions of our nanofilaments. Note that at 3.3 eV, Eg of our Ti02-based nanoparticles is closer to that of bulk anatase as expected (Fig. 4a) [0076] Interestingly (and without being bound to any particular theory or embodiment), here there is no correlation between the Ti3+ content - as deduced from the Li concentration - and the Urbach tails as some have suggested. [29] We thus tentatively conclude that the tails, and the conductivity, arise from point defects. In some of the EELS measurements, the Ti fraction approaches 0.5 (Table 5) which suggests that O/C vacancies form. This comment notwithstanding, more work is needed to understand why some of these films are sometimes conductive.
[0077] To investigate possible applications, we explored the performance of our 2D flakes in lithium-ion batteries, LIBs, and lithium-sulphur, Li-S. The results are shown in Figs. 4b and c, respectively and in both cases, the results are promising. A detailed discussion can be found in SM (see Figs. 17 and 18). In the LIB case, the absence of lithiation and delithiation peaks at 1.64 V and 2.1 V, (inset in Fig. 4b) confirm that this electrode is neither TiCh nor a layered titanate.[30, 31] Moreover, the Coulombic efficiency of the electrode was ~ 99.3% after 200 cycles (Fig. 17d), reflecting a highly efficient electrochemical cycling.
[0078] Lithium sulfur (Li-S) coin cells with a Li anode and a TiC-derived TCO cathode were assembled and cycled. Results are shown in Fig. 4c and are discussed in detail in SM.
[0079] These results are included to confirm the 2D nature of the materials obtained and their potential. However, it is reasonable these results can be greatly enhanced with better understanding of what is obtained. These comments notwithstanding, it is hereby acknowledged that much more work, clearly beyond the scope of this paper, is needed to understand the mechanisms, involved, etc. However, it is fair to say, that these materials show great promise, especially as Li-S cathodes. For example, as shown in Fig. 18b, the capacity was constant at ~ 1000 mAh/g for about 300 cycles before fading.
[0080] Lastly, to further demonstrate the versatility of TCOs we explored their potential for biomedical application and indeed have use in cancer therapy (Fig. 4d). Here mouse 4T1 breast cancer cells and B16-F10 melanoma cells were treated with different concentrations of TiC-derived TCOs for 24 h before a MTT assay was used to measure their viability. At a concentration of 200 pg/ml, the TCO particles could induce cancer cells' death, and were more effective on the 4T1 breast cancer cells than to B16-F10 melanoma cells. Accordingly, one can administer compositions according to the present disclosure to a cancer-containing sample, which administration can induce the cancer cells’ death.
[0081] Conclusion
[0082] We discovered a simple, inexpensive, relatively high-yield, near ambient, fully scalable, one-pot, bottom-up approach to fabricate 2D titanium carbo-oxide films comprised of nanofilaments. By heating 11 different - layered and non-layered Ti-based precursor powders in TMAH at different temperatures (25° to 85 °C) for various times we converted 10 of them to 2D flakes that are anatase-based and are in turn comprised of ~ 6 xlO A2 nanofilaments with substantial C-content. Several of the films were dark in color and some of them were conductive, with conductivities in the 0.01 to 0.05 S/cm range. However, since there was no correlation between the Urbach tails and the fraction of Ti3+ as deduced from the overall Li content, we conclude that the source of the conductivity is not the reduced oxidation state but probably point defects. The TCOs performed well as electrodes in LIB and Li-S batteries. They also show potential in biomedical applications.
[0083] Materials and Methods
[0084] Processing of films
[0085] Our synthesis process entails immersing precursor powders in 25 wt.% TMAH in polyethylene jars that are heated on a hot plate at temperatures that ranged from room temperature (RT) to 85 °C and for durations from 24 h to a week. After reaction with the TMAH, (except for TriSbP, T1B2 and T1O2) a dark black sediment was obtained, collected, and rinsed with ethanol, shook, and centrifuged at 3500 rpm for multiple cycles until a clear supernatant was obtained. Once the supernatant was clear, 30 mL of deionized, DI, water was added to the washed products and shook for 5 mins. After centrifugation at 3500 rpm for 0.5 h, without sonication, a stable colloidal suspension was obtained. Any unreacted powders settled down. The colloid was then vacuum filtered to produce FF some of which were characterized.
[0086] In some cases, an additional step of washing with LiCl solution was conducted and the produced flakes were characterized. A 5M LiCl solution was added to the black colloidal suspension obtained above. This resulted in deflocculation. The sediment was shaken and rinsed with deionized water through centrifugation at 5000 rpm for three cycles. The LiCl/DI water washing process was repeated until the pH was - 7. The washed sediment was then sonicated in a cold bath for 1 h under flowing Ar, shaken for 5 min, then centrifuged at 3500 rpm for 10 min. The colloidal suspension was filtered to produce FFs. The FFs were then left to dry in a vacuum chamber overnight before further characterization.
[0087] In few cases, the black slurry - produced from the reaction of TMAH and TiC - centrifuged (at 5000 rpm for 5 min) directly without the addition of any solvents, the supernatant decanted, the sediment resuspended in 20 mL DI water, shook for 5 min, then centrifuged at 3500 rpm for 30 min. The produced black colloidal suspension was used for XRD (not shown) and TEM inspection.
[0088] The yield was calculated as fraction of the number of moles of Ti in the produced anatase-like structure (molar mass of TiCh is used for simplicity) to those supplied by the precursor. For instance, the yields for TiC and T13AIC2 are 19% and 28%, respectively. In general, the yield is of the order of - 20% depending on starting precursor. The solid loading in our colloidal suspensions is of the order of 10 g/L.
[0089] X-ray diffraction, XRD
[0090] XRD patterns on air dried samples were acquired using a powder diffractometer (Rigaku SmartLab) setup in the Bragg-Brentano geometry with Cu Ka radiations in the 2-65° 2Q range using a 0.02° step size and a dwell time of 1 s/step. We also obtained XRD patterns, in transmission mode, on vertically oriented films.
[0091] Raman Spectroscopy, RS
[0092] Raman scattering spectra were collected at 300 K in air from FF of a number of precursors (Fig. 2b). The samples were probed using a 532- nm laser emitting 3.75 mW of power at the sample and focused to a spot diameter of -0.5 pm. Scattered light was collected in a backs cattering geometry and was dispersed and detected using a single-axis monochromator equipped with a charge-coupled detector array (Horiba XploRA, Edison NJ)
[0093] X-ray photoelectron spectroscopy, XPS
[0094] XPS was performed using a spectroscope (VersaProbe 5000, Physical Electronics, Chanhassen, Minnesota). Monochromatic Al-Ka X-rays with a 200 pm spot size were used. A pass energy of 23.5 eV, with an energy step of 0.05 eV and a step time of 0.5 s was used to gather high-resolution spectra. Number of repeats per scan was 10. XPS spectra were calibrated by setting the major C-C peak to 285.0 eV. Peaks were fit using asymmetric Gaussian/Lorentzian line shapes. The background was determined using the Shirley algorithm. All samples were mounted on a XPS stage using carbon tape.
[0095] Scanning electron microscope, SEM
[0096] Micrographs and elemental compositions were obtained using a SEM, (Zeiss Supra 50 VP, Carl Zeiss SMT AG, Oberkochen, Germany), equipped with an energy-dispersive X-ray spectroscope (EDS, Oxford EDS, Oxfordshire, United Kingdom). The EDS values reported represent the average of at least two measurements at low magnifications of randomly selected areas with an accelerating voltage 15 kV and 60 s dwell time.
[0097] Atomic Force Microscopy, AFM
[0098] Thicknesses of filaments and flakes were obtained with an AFM (Multimode 8 AFM from Bruker Nano Surfaces). A peak force tapping AFM imaging mode was applied to acquire the surface morphology and height profiles. The scanning was conducted with ScanAsyst-Air Silicon Nitride Probes at a scan rate of 0.6 Hz. Topographic images were recorded as the resolution of 256*256 pixels and analyzed by Nano Scope Analysis software.
[0099] Transmission electron microscope, TEM
[00100] TEM imaging and electron diffraction patterns were collected using a JEOL JEM2100F field-emission TEM. The TEM was operated at 200 keV and has an image resolution of 0.2 nm. Images and diffraction patterns were collected on a Gatan USC1000 CCD camera. Scanning transmission electron microscopy, STEM, was carried out in the monochromated and double Cs corrected FEI Titan3 60-300 operated at 300 kV.
[00101] Electron energy loss spectroscopy, EELS
[00102] STEM-EELS spectra were acquired by averaging 100 spectra, acquired for 1 s each at a 0.25 eV/channel energy dispersion, and collection semi-angle of 55 mrad of employed Gatan GIF Quantum ERS post-column imaging filter. Elemental quantification of present edges was performed using built in functions of Digital Micrograph. [00103] X-ray absorption near edge structure, XANES
[00104] The Ti K-edge isotropic XANES spectra were recorded at 54° from the normal to the film using circularly polarized x-rays provided by the first harmonic of the HELIOS-II type helical undulator (HU-52). The x-ray beam was monochromatized using a fixed-exit double crystal monochromator equipped with a pair of Si(l 11) crystals. Total fluorescence yield signal was collected by a Si photodiode mounted in back-scattering geometry. Spectra were corrected for self-absorption effects. The samples were ~ 1 mm thick compressed powered pellets. The isotropic XANES spectra were normalized to an edge jump of unity far above the absorption edge. The photon energy scale was calibrated using the pre-peak maximum in the absorption spectrum of a Ti thin foil that was set to 4965.6 eV. Spot size was 0.4x0.3 mm2. Experiments were performed at European Synchrotron Radiation Facility (ESRF) ID12 beamline in Grenoble
[00105] Electrical resistivity
[00106] Electrical resistivity measurements were performed using a four-point probe device (Loresta-AX MCP-T370, Nittoseiko, Japan) at RT, then converted into electrical conductivity values.
[00107] Thermogravimetric Analysis, TGA
[00108] A thermobalance (TA Instruments Q50, New Castle DE) was used for the TGA analysis. Small pieces of FF (~ 20 mg) were heated in sapphire crucible at 10 °C/min, under purging Ar at 10 mL/min, to 800 °C. In one experiment we used a thermobalance attached to a mass-spectrometer. In these measurements a thermal analyzer (TA instruments, SDT 650, Discovery Series) coupled with a mass spectrometer (TA instruments Discovery Series) operating at 40 V ionizing potential was used. Samples were held at RT for 0.5 h then heated to 800°C at 10°C/min under dry compressed air flow at 50 mL/min. The carrier gasses and evolved gas products from the sample were measured by scanning over the 1-100 atomic mass unit range. The ion current for each m/z (mass/charge ratio) was normalized by the initial sample weight.
[00109] UV-vis.
[00110] UV-VIS spectra were recorded using spectrophotometer (Evolution 300 UV -Visible, Thermo Scientific). Measurements were performed in transmission mode on 1-1 Opm thick films coated onto quartz slides. [00111] DFT calculations
[00112] First-principles calculations were carried out using the Vienna ab initio simulation package (V ASP). [32] The projector augmented wave method (PAW) was used together with a plane wave basis expanded to a kinetic energy cutoff of 600 eV. Exchange-correlation effects were described within the generalized gradient approximation using the Perdew, Burke, and Emzerhof (PBE) functional [33] Brillouin zone integration was performed using the Gaussian smearing method with a smearing width of 0.05 eV. The electronic configurations of the pseudopotentials used were C: [He]2S22P2, O: [He]2s22p4 and Ti_sv: [Ne]3s23p63d24s2. The calculation supercells were constructed to consist of various anatase (101) atomic layers using a slab model, with periodicity along the a and b axes of the supercell, which correspond to the [100] and [101] directions of bulk anatase, respectively. The supercell geometry and atom positions were relaxed until the force on each atom <5 meV/A. A vacuum region of 15 A was added along the oaxis (in new coordinate system) of the supercell to eliminate interactions between periodic images perpendicular to the slabs. For the structural optimization, the first Brillouin zone was sampled by a 16x6x1 k-point sampling, while a 8x3x1 supercell together with a 2x2x1 k-point sampling was used for the phonon calculations.
[00113] Electrochemical Measurements
[00114] Lithium ion battery, LIBs
[00115] To evaluate electrochemical performance of TCO as electrode material as LIB material, we tested it in half-cell configuration against Li metal. The TCA working electrodes were fabricated by drop-casting a slurry of active materials with binder and carbon additive on a carbon coated copper foil. The slurry was prepared by mixing 40.0 mg of active materials, 5.0 mg of poly(vinylidene fluoride) (PVDF, Sigma Aldrich, US) binder in N-methyl-2-pyrrolidinone (NMP, 99.5%, Acros Organics, Extra Dry over Molecular Sieve, Germany) solvent, and 5.0 mg of carbon black. The as-prepared electrodes were dried overnight at 60 °C. The electrode mass loading was ~ 1.2- 1.5 mg/cm2. Two-electrode CR2032-type coin cells were assembled in an Ar-filled glovebox with O2 and H2O < 0.1 ppm. Li metal foil was used as a counter electrode. 1M L1PF6 in ethylene carbonate (EC)/ ethyl methyl carbonate (EMC) with 3:7 (by weight) and glass fibers were used as electrolyte and separator, respectively. CV and galvanostatic charge- discharge testing were performed with a cut-off electrochemical voltage window of 0.001- 3.0 V vs Li/Li+ using an electrochemical workstation (BioLogic VMP3) and a cycler (Landt CT2001A,). Electrochemical impedance spectroscopy with frequency from 100 kHz to 10 mHz were conducted in a electrochemical workstation (BioLogic VMP3).
[00116] Sulphur -Lithium Cells
[00117] To evaluate the performance of TCO as sulfur host in Li-S batteries, we prepared TCO/S cathodes using a slurry-based method. Briefly, the slurry was prepared by mixing 35 wt% vacuum-dried TCOs, 35 wt% sulphur, S, with 20 wt% conductive carbon (Alfa Aesar, Super P) and 10 wt.% battery grade PVDF binder (MTI Corp., USA). The materials were hand-ground with a mortar and pestle until the mixture appeared uniform. Later, N-Methyl-2-pyrrolidone (TCI, USA) was slowly added until the required visible consistency and uniformity of the slurry were achieved (~25 minutes). The slurry was later cast on aluminum foil using a doctor blade (MTI Corp., USA) with a thickness of 20 pm. Once cast, the slurry was kept in a closed fume hood for 2 h before transferring to a vacuum oven where it was dried at 50 °C for 12 h.
[00118] The dried TCO/S cathodes were cut using a hole punch (diameter 11 mm) to form disks. The electrodes were then weighed and transferred to an Ar-filled glove box (MBraun Lab star, O2 < 1 ppm, and H2O < 1 ppm). The CR2032 (MTI Corporation and Xiamen TMAX Battery Equipment) coin-type Li-S cells were assembled using TCO/S cathodes, a 15.6 mm diameter, 450 pm thick Li disk anode (Xiamen TMAX Battery Equipment) a tri-layer separator (Celgard 2325), and a stainless-steel spring and two spacers along with the electrolyte. The electrolyte, with 1 M LiTFSi with 1 wt% L1NO3 in a mixture of 1,2-dimethoxy ethane and 1,3-dioxolane at a 1:1 volume ratio, was purchased (TMAX Battery Equipment, China) and according to manufacturer contained trace amounts of oxygen and moisture (H2O < 6 ppm and O2 < 1 ppm). Assembled coin cells were rested at their open-circuit potential for 10 h before performing the electrochemical experiments at RT. Cyclic voltammetry was performed at a scan rate of 0.1 mV.s 1 between voltages 1.8 and 2.6 V wrt Li/Li+ using a potentiostat (Biologic VMP3). Prolonged cyclic stability tests were carried out with a battery cycler (Neware BTS 4000) at different C-rates (where 1 C = 1675 mAh.g 1) between voltages of 1.8 and 2.6 V. The Li-S cells were conditioned for 2 cycles at 0.1 C and 0.2 C, before undergoing long cycling at 0.5 C.
[00119] Biological Tests
[00120] One day before treatment, 4T1 and B16-F10 cells were added into a 96 well plate at a density of 10000 cells/well. The cells were cultured at 37 °C/5% CO2 in RPMI-1640 medium supplemented with 10% fetal bovine serum and 100 IU/mL penicillin/streptomycin for 24 h. The cells were then treated with TiC-based TCOs at concentrations of 10 pg/mL, 50 pg/mL or 200 pg/mL. After 24 h treatment, athiazolyl blue tetrazolium bromide (MTT) assay was performed according to manufacturer's protocol. The absorbance at 570 nm and 630 nm was measured. Relative cell viability was obtained by comparing to the absorbance of untreated cells. All measurements were performed in triplicate. Data was analyzed using two-way ANOVA with post-hoc Tukey’s test.
[00121] [1] K.S. Novoselov, et al., Science 353 (2016) 461.
[00122] [2] D. Deng, K.S. Novoselov, Q. Fu, N. Zheng, Z. Tian, X. Bao, Nat.
Nanotechnol. 11 (2016) 218-230.
[00123] [3] K.S. Novoselov, Science 306 (2004) 666-669.
[00124] [4] K.S. Novoselov, D. Jiang, F. Schedin, T.J. Booth, V.V. Khotkevich,
S.V. Morozov, A.K. Geim, PNAS 102 (2005) 10451-10453.
[00125] [5] F. Xia, H. Wang, Y. Jia, Nat. Commun. 5 (2014) 4458-4458.
[00126] [6] M. Naguib, M. Kurtoglu, V. Presser, J. Lu, J. Niu, M. Heon, L.
Hultman, Y. Gogotsi, M.W. Barsoum, Adv. Mater. 23 (2011) 4248-4253.
[00127] [7] L. Verger, C. Xu, V. Natu, H.-M. Cheng, W. Ren, M.W. Barsoum,
Curr. Opin. Solid State Mater. Sci. 23 (2019) 149-163.
[00128] [8] S.L. Swartzen-Allen, E. Matijevic, Chem. Rev. 74 (1974) 385-400.
[00129] [9] L. Verger, V. Natu, M. Carey, M.W. Barsoum, Trends Chem. 1
(2019) 656-669.
[00130] [10] T. Yang, T.T. Song, M. Callsen, J. Zhou, J.W. Chai, Y.P. Feng, S.J.
Wang, M. Yang, Adv. Mater. Interfaces 6 (2019) 1801160.
[00131] [11] Z. Sun, T. Liao, Y. Dou, S.M. Hwang, M.-S. Park, L. Jiang, J.H.
Kim, S.X. Dou, Nat. Commun. 5 (2014) 3813. [00132] [12] J. Xuan, Z. Wang, Y. Chen, D. Liang, L. Cheng, X. Yang, Z. Liu,
R. Ma, T. Sasaki, F. Geng, Angew. Chem. (2016).
[00133] [13] D.N. Miller, A.K. Azad, H. Delpouve, L. Quazuguel, J. Zhou, A.
Sinha, P. Wormald, J.T.S. Irvine, J. Mater. Chem. A 4 (2016) 5730-5736.
[00134] [14] M. Ghidiu, M.W. Barsoum, J. Amer. Ceram. Soc. 100 (2017) 5395-
5399.
[00135] [15] Yunxia Chen, Xin He, Xiujian Zhao, Qihua Yuan, X. Gu, J. Colloid
Interface Sci. 310 (2007) 171-177.
[00136] [16] Frederic Labat, Philippe Baranek, C. Adamo, J. Chem. Theory
Comput. 4 (2008) 341-352.
[00137] [17] Z. Liu, K. Ooi, H. Kanoh, W. Tang, T. Tomida, Langmuir 16
(2000) 4154-4164.
[00138] [18] S.L. Brock, et al. , J. Phys. Chem. B 103 (1999) 7416-7428.
[00139] [19] Z. Tan, K. Sato, S. Ohara, Adv Powder Technol 26 (2015) 296-302.
[00140] [20] M. Ghidiu, J. Halim, S. Kota, D. Bish, Y. Gogotsi, M.W. Barsoum,
Chem. Mater. 28 (2016) 3507-3514.
[00141] [21] L. Verger, V. Natu, M. Ghidiu, M.W. Barsoum, J. Phys. Chem. C
20044-20050 (2019) 19725-19733.
[00142] [22] X. Dong, J. Tao, Y. Li, H. Zhu, Appl. Surf 256 (2010) 2532-2538.
[00143] [23] A.D. Dillon, M.J. Ghidiu, A.L. Krick, J. Griggs, S.J. May, Y.
Gogotsi, M.W. Barsoum, A.T. Fafarman, Adv. Funct. Mater. 26 (2016) 4162-4168.
[00144] [24] M. Ghidiu, M.R. Lukatskaya, M.-Q. Zhao, Y. Gogotsi, M.W.
Barsoum, Nature (2014).
[00145] [25] C.J. Zhang, B. Anasori, A. Seral-Ascaso, S.-H. Park, N. McEvoy,
A. Shmeliov, G.S. Duesberg, J.N. Coleman, Y. Gogotsi, V. Nicolosi, Adv. Mater. 29 (2017) 1702678.
[00146] [26] P. Makula, M. Pacia, W. Macyk, J. Phys. Chem. 9 (2018) 6814-
6817.
[00147] [27] A.S.D. Wang, T. Sasaki, Chem. Rev. 114 (2014) 9455-9486.
[00148] [28] T. Liao, Z. Sun, S.X. Dou, ACS Appl. Mater. Interfaces 9 (2017)
8255-8262. [00149] [29] D.-e. Gu, Y. Lu, B.-c. Yang, Y.-d. Hu, Chem. Commun. (2008)
2453-2455.
[00150] [30] Y. Dong, M. Yu, Z. Wang, Y. Liu, X. Wang, Z. Zhao, J. Qiu, Adv.
Funct. Mater. 26 (2016) 7590-7598.
[00151] [31] J. Xu, C. Jia, B. Cao, W. Zhang, Electrochim. Acta 52 (2007) 8044-
8047.
[00152] [32] G. Kresse, J. Furthmiiller, Phys. Rev. B 54 (1996) 11169-11186.
[00153] [33] J.P. Perdew, K. Burke, M. Emzerhof, Phys. Rev. Lett. 77 (1996) 3865-3868.
[00154] Supplementary Disclosure
[00155] Rationale for LiCl Washing
[00156] Based on earlier work on ion exchange and colloidal stability of 2D materials [1-9] we implemented a LiCl washing step for the following reasons:
[00157] To rid the interlayer space of the TMA cations. This was useful because in some cases, the TMA cations resulted in non-conducting films.
[00158] To prove the existence of exchangeable cations between the layers. Had there been no exchangeable cations, the Li+ ions would not have intercalated between the layers.
[00159] Knowing the fractions of resulting crystalline phases after heating the filtered films, FF, to 800 °C in Ar, allowed us to estimate the Ti3+ content.
[00160] X-Ray Diffraction
[00161] Not surprisingly, X-ray diffraction, XRD of films in the horizontal orientation did not shed much light on the underlying structure. Instead, we obtained patterns of vertically oriented films using a setup similar to Ghidiu et al. [10] To obtain the films 1-3 ml of a colloidal suspension was drop-cast, using a pipette, onto a Kapton tape mounted on a glass slide (inset in Fig. 7a). Three layers of colloidal suspension were drop- cast with drying in between applications. Drying was carried out using a fan at room temperature, RT, inside a petri dish. The drop-cast sample was secured to a vertical sample holder using double-sided tape (Fig. 7a). The sample holder was then aligned to maximize the signal through the sample.
[00162] Crystallography [00163] One may note that the coordinate system we are using here is not that of bulk anatase, but the one shown in bottom left of Fig. lc. Following our recipe, the grown nfs-based 2D flakes are preferentially oriented along (110) which is the lowest energy plane in bulk anatase (i.e. anatase coordinate system). To be consistent with the 2D literature, in our system, the flakes’ stacking direction is along c-axis. Said otherwise, in our coordinate system, this is the (00/) plane.
[00164] Transmission Electron Microscope, TEM
[00165] The TEM images show that the aligned regions are a fraction of the total. In a sizable fraction, the nanofilaments are not aligned, but randomly oriented in the plane of the flakes. This has also been confirmed by selected area diffraction pattern (SAD) that showed diffraction rings for most of the characterized flakes.
[00166] Electron Energy Loss Spectroscopy, EELS
[00167] The EELS spectra on 5 different particles were measured on TiC-based flakes obtained after heating in TMAOH for 3d at 50 °C and ethanol washed. Figure 2c includes carbon -K edge at -280 eV energy loss, titanium -L3,2 peaks at -450 eV energy loss and oxygen -K edge at -530 eV energy loss. All spectra are normalized to the Ti edge peak intensity. Thicker particles exhibit a steeper background, which is more easily seen at the low energy of the spectrum. The top and bottom spectra exhibit a pronounced lower intensity compared to the three particles in the middle. Among the 5 particles, the top and bottom spectra contain approximately the same amount of C, while for the three in the middle (2, 3 and 4) the chemistry was consistent aTi:C:0 atomic ratio of- 1:1:1. All spectra also show a minor amount of N-K (not shown) at -400 eV energy loss. For the remainder of this paper, this small amount of N will be ignored. The results of these spectra are summarized in Table 5. The C is presumed to be in the backbone of the structure because the intensity of the C-loss peak did not change with time under the electron beam.
[00168] Crucially two of the particles contained a significantly higher ratio of Ti. In one case, the Ti atomic fraction is close to 0.5. This suggests that during the process the Ti atoms are chemically reduced to an average oxidation state of +2.
[00169] One may note here that the C is presumed to originate from within the structure since the intensity of the various peak did not change with extended illumination under the beam, which could otherwise come from contaminated samples. The Ti/C ratio did not change even after heating to 500 °C in the TEM chamber.
[00170] X-ray Absorption Near Edge Structure, XANES,
[00171] The XANES experiments were performed at the ESRF beamline ID12 at the Ti K-edge on Ti-derived films. XANES spectra at the K-edge of transition metals are dominated by dipolar transitions to the unoccupied 4p states with usually structured pre edge peaks that are associated with transitions into 4p-3d hybridized states. [11] The energy position of the absorption edge, and more specifically the pre-edge peaks are commonly related to the oxidation state and coordination of the absorbing atom. A comparison of the XANES spectrum of our TCO film (Fig. 2d) with the those of reference compounds for Ti4+ (anatase), TiC, T13AIC2 and Ti3+ (TiCb) indicate that the average Ti oxidation state in the TCO films is between 3+ and 4+. These result also clearly confirm our material is not pure anatase, i.e. anatase without C. It is also neither TiC nor a MAX phase.
[00172] Both covalent bonding and the 3d-count could lead to an energy shift of the K-edge XANES spectra of Ti. The former mechanism is mainly manifested at the main edge. However, the energy positions of weak features below the main edge (arising from quadrupolar transitions ls->3d) are dominated by the effect of the 3d occupation. Comparing the first derivative of the XANES spectra (inset in Fig. 2d) in the energy range from 4964 eV to 4968 eV clearly indicates that the oxidation state of Ti in TiC is close to 3+ as in the reference compound TiCb. On the contrary, TiCO contains both Ti3+ and Ti4+ states since there are two peaks in their derivative spectrum and the energy positions of these peaks coincide with the peak of TiCb and the first peak of T1O2.
[00173] X-ray Photoelectron Spectroscopy, XPS
[00174] Typical XPS spectra of all films are compared in Figure 11. The peaks were fit and the results are summarized in Table 4. The Ti:0 ratios of the films are summarized in Table 7. The latter were obtained from the areas of the Ti peaks at ~ 459 eV peak and the O peaks at ~ 530 eV peak. Here the ratio is roughly 1:3.
[00175] For the C Is spectra (second column in Fig. 11) there are three peaks, the largest of which is centered around a binding energy, BE, of ~ 285 eV, the two smaller peaks are centered around ~ 286.5 eV and 288.5 eV. These coincide with the C-C, C-OH, and -COOH BEs, respectively, generally reported in the literature. [12] We have recently shown that in MXenes, when the C atoms are surrounded by 6 Ti atoms their BE is 282 eV.[13] Here there was no peak at 282 eV consistent with the fact that C is not surrounded by 6 Ti atoms. In our structure, the C is bonded to 4 Ti atoms and it thus not surprising that their BEs are higher than 282 eV. After careful consideration we concluded that the C-peak in our TCO overlaps with the adventitious C-C peak.
[00176] As shown in Fig. 11 the Ti 2p3/2 BE is a weak function of processing.
For example, the BEs after ethanol washing, LiCl and even after TGA to 800 °C, are all quite comparable indeed and thus the values obtained on these films can be considered representative of all BEs for all processing conditions. When the films were heated in air the XPS spectra shifted (not shown).
[00177] Fig. 13 shows that, except in the case of TriSiC2 for which a Si signal was observed (Fig. 13c), all other films were comprised of only three elements, Ti, O and C. There was also no Cl between the layers confirming that we are not dealing with double layered hydroxides (Fig. 13b).
[00178] Thermogravimetric Analysis, TGA
[00179] Samples that were ethanol and LiCl washed were placed in a TGA and heated to 800 °C in Ar. The results are shown in Fig. 14. With the notable exception of the TiCh derived films and an ethanol washed film (two outliers in Fig. 14a) the overall weight loss was about 15 %. The one run carried out in air on a TiC-derived, LiCl washed film showed identical results to those heated in Ar. In this case, however, the TGA was attached to a mass spectrometer that showed that the only gas evolved up to 400 °C was water (Fig. 14 b and c). Beyond that temperature, some CO2 was evolved.
[00180] The reason T1O2 is an outlier is because we have shown by XRD and TEM (Fig. 16) that what forms in this case is not a 2D structure, but rather nano-anatase particles. It is instructive at this point to compare the XRD diffraction patterns of anatase and our 2D flakes. In the latter the (104) and (105) peaks do not exist and the 63° 20 peak in anatase shifts much closer to 60° 20 (Fig. 16a).
[00181] Rietveld Analysis of Samples Heated in TGA to 800 °C
[00182] The results of Rietveld analyses, RA, of XRD patterns of FF heated to 800 °C in Ar in a TGA (Fig. 15) were caried out and the fractions of the various phases were quantified. The results are tabulated in Table 8. In most cases, the resulting phases were the Li-titanate, LTA, Li1.33Ti1.66O4 and anatase or rutile, T1O2. With most c2 values were < 2, the fits were quite good. Note that because the films derived from T1O2 is not layered, the LTA volume fraction is by far the lowest.
[00183] Atomic Force Microscopy, AFM
[00184] To better understand the dimensions and make up of our 2D flakes we carried out an AFM study on the 2D flakes and nanoribbons. The results shown in Fig. 3c and d confirm that the obtained 2D flakes are comprised of self-aligned nanofilaments.
[00185] To obtain the nanofilaments we heated TiC powders in TMAH at 80 °C for 5 d. After washing with water, a colloidal suspension was obtained. When the latter was spin coated at 1000 rpm for 10 s on a glass slide the AFM showed an unmistakable fiber structure, where the filaments were all aligned in more or less the same direction (Fig. 3c). The colloidal suspension was then diluted 500 times and drop cast on a substrate. This resulted in the separation of the filaments (Fig. 3d). When the AFM was traced across the blue line shown in Fig. 3d, the resulting profile (inset in Fig. 3d) showed that the thinnest fibers were « 1.5 nm thick.
[00186] Lithium-ion battery, LIB
[00187] For the LIB work, CR2032-type coin cells were assembled to investigate the electrochemical performance of Ti3AlC2-derived electrodes. The cyclic voltammetry, CV, curves obtained at a scan rate of 0.1 mV s 1, in the 0.001-3.0 V vs Li/Li+ voltage window (inset in Fig. 4b) are quite similar to those in MXene literature. [14, 15]
[00188] Figure 4b in main paper shows the galvanostatic charge/discharge voltage profiles at a specific current of 20 mA g 1, the initial lithiation and delithiation specific capacities are 714 and 265 mAh g 1, respectively. The specific capacity loss in the first lithiation process can be attributed to the solid electrolyte interphase (SEI) layer formation below 0.85 V and other irreversible reactions. [16] The specific capacity stabilizes after two cycles. The stable lithiation and delithiation specific capacities of 210 and 209 mAhg 1, respectively, are maintained after 5 cycles. Figure 17a, plots the electrochemical impedance spectroscopy of the electrode, showing low system resistance (4 W) and small charge transfer resistance (18 W), which support the electrochemical performance observed. Rate handling capability results are shown in Figure 17b. At 500 mA g 1 a reversible capacity of - 110 mAh g_1can be maintained. Even at 1000 mA g 1, a reversible capacity of - 80 mAh g 1 can be achieved, and by returning to 20 mA g 1, the capacity recovered to -180 mAh g 1. As shown in Figure 17c and d, the as-prepared TCO electrode exhibits excellent cycling stability performance at a specific current of 100 mA g 1. The electrode shows a specific capacity of 155 mAhg 1 over 200 cycles. Moreover, the Coulombic efficiency of the electrode is - 98.9% after 30 cycles, reflecting a highly efficient electrochemical cycling.
[00189] Lithium Sulphur, Li-S electrodes
[00190] Figure 18a, plots typical CV curves in the 1.8-2.6 V (vs. Li/Li+) range at a scan rate of 0.1 mV s 1. The CV curves show two sharp and distinct cathodic and one anodic peak. The first cathodic peak at 2.3 V is ascribed to S reduction (12) to long-chain lithium polysulfides (LiPs), while the second peak is related to a subsequent reduction of LiPs to Li26/Li2S.[17] The peak shifts after the first anodic peak are possibly due to nucleation/reorganization during the redeposition of the LiPs back to 12. Figure 4c, displays typical discharge plateaus consistent with the CV results. The TCO/S composite electrodes deliver capacities of 1300, 1200, 1050 mAh g 1 at 0.1, 0.2 and 0.5 C rates, respectively. Such high capacity can be associated with the TiCO conductivity, coupled with possible surface-active sites that bind to the LiPs. To evaluate the long-term stability, of the cathodes they were cycled at 0.5 C at a S loading of 0.83 mg cm2. Figure 14b, shows the cell delivers an initial capacity of -1300 mAh g 1, which stabilizes to -1000 mAh g 1 after the first 5 cycles. This initial drop is associated with the two conditioning cycles at low rate of 0.1 and 0.2 C. The composite delivers a capacity of -1000 mAh g 1 after ~ 300 cycles with around 100 % retention. The capacity drops after 300 cycles. These values are excellent given that the cathode was crudely produced by a slurry blend - using a mortar and pestle - of the TCO flakes and commercially-purchased S powders.
[00191] Mesoscopic materials
[00192] We heated 50 g of T1B2 powder in 500 mL of 25 % TMAH solution at 80 C for 3 days in a polyethylene bottle and shaken using a mechanical lab shaker. After 3 days in the shaker, the resulting suspension was allowed to settle and the liquid was decanted. Then 500 mL ethanol was added and the suspension and again allowed to settled and the liquid was decanted. The ethanol washing was repeated for a total of 3 times. [00193] After decantation of the supernatant, the resulting sediment was washed with 500 mL of a 5M LiCl solution at RT for 4 h. This was followed by decantation of the liquid. The process was repeated with water for another 4 h. After a second water washing the supernatant was decantated which resulted in a grey sediment. The resulting sediment was dried in open air at 40C overnight then hand-ground to produce a fine powder.
[00194] XRD pattern of the powder showed low angle peak with d-spacing of 9.4 A, non-basal peaks at 25° and 48°, that correspond to 2D anatase. The (104) and (105) peaks were missing. Some low intensity peaks that belong to unreacted the TiB2 precursor remained. SEM micrographs (Fig. 19) of the resulting powder revealed an even distribution of well separated mesoporous particles roughly 10 pm in size. The mesoporous particles can be made of ligaments that are few-mi crons long and less than 100 nm in diameter. The mesoporous particles can be used in, e.g., drug delivery, energy storage, and devices. As an example a therapeutic can be associated with the mesoporous particles (e.g., adsorbed to, intercalated into, etc.), which therapeutic-laden particles can be introduced to a subject and deliver the therapeutic to the subject.
[00195] References and Notes
[00196] [1] A.P. Ferris, W.B. Jepson, J. Colloid Interface Sci. 51 (1975) 245-
259.
[00197] [2] M. Ghidiu, J. Halim, S. Kota, D. Bish, Y. Gogotsi, M.W. Barsoum,
Chem. Mater. 28 (2016) 3507-3514.
[00198] [3] M. Ghidiu, S. Kota, J. Halim, A.W. Sherwood, N. Nedfors, J. Rosen,
V.N. Mochalin, M.W. Barsoum, Chem. Mater. 29 (2017) 1099-1106.
[00199] [4] W.G. Lawrence, J. Am. Ceram 41 (1958) 136-140.
[00200] [5] L. Verger, V. Natu, M. Ghidiu, M.W. Barsoum, J. Phys. Chem. C
20044-20050 (2019) 19725-19733.
[00201] [6] M.M. Gudarzi, Langmuir 32 (2016) 5058-5068.
[00202] [7] G. Lagaly, S. Ziesmer, J. Colloid Interface Sci. 100-102 (2003) 105-
128.
[00203] [8] T. Missana, A. Adell, J. Colloid Interface Sci. 230 (2000) 150-156.
[00204] [9] V. Natu, M. Sokol, L. Verger, M.W. Barsoum, J. Phys. Chem. C 122
(2018) 27745-27753. [00205] [10] M. Ghidiu, M.W. Barsoum, J. Amer. Ceram. Soc. 100 (2017) 5395-
5399.
[00206] [11] A. Rogalev, F. Wilhelm, Phys. Met. Metallogr. 116 (2015) 1285-
1336.
[00207] [12] T.L. Barr, S. Seal, J. Vac. Sci. Technol 13 (1995) 1239-1246.
[00208] [13] V. Natu, M. Benchakar, C. Canaff, A. Habrioux, S. Celerier, M.W.
Barsoum, Matter 4 (2021) 1224-1251.
[00209] [14] J. Luo, X. Tao, J. Zhang, Y. Xia, H. Huang, L. Zhang, Y. Gan, C.
Liang, W. Zhang, ACS Nano 10 (2016) 2491-2499.
[00210] [15] B. Ahmed, D.H. Anjum, M.N. Hedhili, Y. Gogotsi, H.N. Alshareef,
Nanoscale 8 (2016) 7580-7587.
[00211] [16] M. Naguib, J. Come, B. Dyatkin, V. Presser, P.-L. Tabema, P.
Simon, M.W. Barsoum, Y. Gogotsi, Electrochem. commun. 16 (2012) 61-64.
[00212] [17] A. Manthiram, Y. Fu, S.-H. Chung, C. Zu, Y.-S. Su, Chem. Rev.
114 (2014) 11751-11787.
[00213] Aspects
[00214] The following Aspects are illustrative only and do not limit the scope of the present disclosure or the appended claims.
[00215] Aspect 1. A composition, comprising: a plurality of oxide-based nanofilaments and/or subnanofilaments, and optionally an amount of carbon. (As described herein, the nanofilaments can comprise titanium.) The composition can be present as a mesoporous powder in which the powder particulates comprise the oxide- based nanofilaments and/or subnanofilaments.
[00216] Aspect 2. The composition of Aspect 1, wherein at least some of the nanofilaments and/or subnanofilaments have a width in the range of from about 3 to about 50 A. The width can be, e.g., from about 3 to about 50 A, from about 5 to about 45 A, from about 7 to about 40 A, from about 9 to about 35 A, from about 12 to about 30 A, from about 15 to about 20 A, and all intermediate values and combinations.
[00217] The composition can be comprised in a suspension, e.g., in a solution or an ink, which ink can be printable. With specific regard to inks, inks can be sprayed, printed, or otherwise applied to a substrate. An ink can include solvents, binders, and the like.
[00218] Aspect 3. The composition of Aspect 2, wherein at least some of the nanofilaments and/or subnanofilaments have an average width in the range of from about 7 to about 20 A.
[00219] Aspect 4. The composition of any one of Aspects 1-3, wherein the nanofilaments and/or subnanofilaments define anon-circular cross-section.
[00220] Aspect 5. The composition of Aspect 4, wherein the nanofilaments and/or subnanofilaments define a cross-sectional aspect ratio of from greater than 1 to about 10. For example, the cross-sectional aspect ratio can be from 1.1 to 10, from 1.5 to 9, from 1.8 to 8, from 2.2 to 7, from 2.5 to 6, from 2.8 to 5, or even from 3.2 to 4.
[00221] Aspect 6. The composition of Aspect 5, wherein the nanofilaments and/or subnanofilaments define a cross-sectional aspect ratio of from about 2 to about 5.
[00222] Aspect 7. The composition of any one of Aspects 1-6, wherein the nanofilaments and/or subnanofilaments have an average cross-sectional area in the range of from about 10 to about 100 A2. For example, the average cross-sectional area can be the range of from about 10 to about 100 A2, from about 15 to about 90 A2, from about 20 to about 80 A2, from about 30 to about 70 A2, from about 40 to about 60 A2, or even about 50 A2.
[00223] Aspect 8. The composition of any one of Aspects 1-7, wherein at least some of the nanofilaments and/or subnanofilaments have a length in the range of from 1 nm to about 25 pm. The length can be, e.g., from about 1 nm to about 25 pm, from about 10 nm to about 20 pm, from about 50 nm to about 10 pm, from about 100 nm to about 5 pm, or from about 250 nm to about 2 pm.
[00224] Aspect 9. The composition of Aspect 8, wherein at least some of the nanofilaments and/or subnanofilaments have a length in the range of from 1 nm to about 1 pm.
[00225] Aspect 10. The composition of any one of Aspects 1-9, wherein the nanofilaments and/or subnanofilaments are comprised in a plurality of flakes; the nanofilaments and/or subnanofilaments can self-assemble into the flakes. Without being bound to any particular theory or embodiments, the nanofilaments and/or subnanofilaments can be aligned in a plane; and a flake can include two or more layers of aligned nanofilaments and/or subnanofilaments, which can in turn provide a flake that is a well-ordered stack of nanofilament and/or subnanofilament layers. The nanofilaments can be self-aligning.
[00226] Aspect 11. The composition of Aspect 7, wherein at least some of the plurality of flakes lie in a common plane. The flakes can be well-stacked along the stacking direction. The nanofilaments and/or subnanofilaments can result in in XRD patterns that are typical of 2D materials, i.e., only one family of planes diffract. Without being bound to any particular theory or embodiment, the nanofilaments and/or subnanofilaments can self-assemble into 2D flakes.
[00227] Aspect 12. The composition of any one of Aspects 1-11, further comprising a pharmaceutically acceptable carrier.
[00228] Aspect 13. The composition of any one of Aspects 1-12, further comprising one or more materials that are fatal to cancer cells.
[00229] Aspect 14. The composition of any one of Aspects 1-13, further comprising a binder. Such a binder can be, e.g., a glue, an adhesive, or other matrix material.
[00230] Aspect 15. The composition of Aspect 14, wherein the binder comprises a polymer.
[00231] Aspect 16. The composition of any one of Aspects 1-15, wherein the nanofilaments and/or subnanofilaments exhibit a XRD pattern that, when compared to a XRD pattern of nano- or bulk anatase, exhibit reduced (104) and (105) peaks at around 38° and about 55° two theta (2Q). The disclosed nanofilaments and/or subnanofilaments can, in some embodiments, exhibit a Raman spectrum that is quite similar to that of bulk anatase, but can differ from bulk anatase in terms of the XRD spectrum, as described herein.
[00232] Aspect 17. A device, the device comprising a composition according to any one of Aspects 1-16.
[00233] Aspect 18. The device of Aspect 17, wherein the device comprises an electrode. [00234] Aspect 19. The device of Aspect 17, wherein the device is characterized as an energy storage device. Such a device can be, e.g., a battery, a supercapacitor, and the like. A device can be rechargeable, but can also be disposable. Such a device can be comprised in a mobile computing device, a mobile communications device, a computing device, an illumination device, a signal transmitted, a signal receiver,
[00235] Aspect 20. The device of Aspect 18, wherein the electrode comprises a composition according to any one of Aspects 1-16.
[00236] Aspect 21. The device of Aspect 17, wherein the device comprises a dispenser, the dispenser having disposed therein the composition according to any one of Aspects 1-16. A dispenser can be, e.g., a syringe, a nozzle, and the like. Such a dispenser can be used to deliver the composition (e.g., according to any one of Aspects 1-16) to a subject (e.g., a human patient) and/or to a sample obtained from a patient. Such a sample can be, e.g., a blood sample.
[00237] Aspect 22. A method, comprising operating a device according to Aspect 17.
[00238] Aspect 23. A method, comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non- water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting being performed under conditions sufficient to give rise to a nanofilamentous (and/or subnanofilamentous) product. The product can self-assemble into 2D flakes.
[00239] Example carbides include, e.g., titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, niobium carbide, tantalum carbide, chromium carbide, molybdenum carbide, tungsten carbide, iron carbide, and the like. Example nitrides include, e.g., aluminum nitride, boron nitride, calcium nitride, cerium nitride, europium nitride, gallium nitride, indium nitride, lanthanum nitride, lithium nitride, magnesium nitride, niobium nitride, silicon nitride, strontium nitride, tantalum nitride, titanium nitride, vanadium nitride, zinc nitride, zirconium nitride, and the like. [00240] Example borides include, e.g., aluminium diboride, aluminium dodecaboride, aluminium magnesium boride, barium boride, calcium hexaboride, cerium hexaboride, chromium(III) boride, cobalt boride, dinickel boride, erbium hexaboride, erbium tetraboride, hafnium diboride, iron boride, iron tetraboride, lanthanum hexaboride, magnesium diboride, nickel boride, niobium diboride, osmium boride, plutonium borides, rhenium diboride, ruthenium boride, samarium hexaboride, scandium dodecaboride, silicon boride, strontium hexaboride, tantalum boride, titanium diboride, trinickel boride, tungsten boride, uranium diboride, yttrium boride, zirconium diboride, and the like.
[00241] Example phosphides include, e.g., alminium gallium indium phosphide, aluminium gallium phosphide, aluminium phosphide, bismuth phosphide, boron phosphide, cadmium phosphide, calcium monophosphide, calcium phosphide, carbon monophosphide, cobalt(II) phosphide, copper(I) phosphide, dysprosium phosphide, erbium phosphide, europium(III) phosphide, ferrophosphorus, gadolinium phosphide, gallium arsenide phosphide, gallium indium arsenide antimonide phosphide, gallium phosphide, holmium phosphide, indium arsenide antimonide phosphide, indium gallium arsenide phosphide, indium gallium phosphide, indium phosphide, iron phosphide, lanthanum phosphide, lithium phosphide, lutetium phosphide, neodymium phosphide, niobium phosphide, phosphide carbide, phosphide chloride, phosphide silicide, -plutonium phosphide, praseodymium phosphide, samarium phosphide, scandium phosphide, sodium phosphide, strontium phosphide, telluride phosphide, terbium phosphide, thulium phosphide, titanium(III) phosphide, uranium monophosphide, ytterbium phosphide, yttrium phosphide, zinc diphosphide, zinc cadmium phosphide arsenide, and zinc phosphide.
[00242] Example aluminides include, e.g., magnesium aluminide, titanium aluminide, iron aluminide, and nickel aluminide.
[00243] Example silicides include, e.g., nickel silicide, sodium silicide, magnesium silicide, platinum silicide, titanium silicide, tungsten silicide, and molybdenum silicide.
[00244] Without being bound to any particular theory or embodiment, mono-, binary, or ternary, or higher carbides, nitrides, borides, phosphides, aluminides, or silicides that comprise titanium are particularly suitable. Similarly, titanium sponge is considered a particularly suitable form of titanium metal for use with the disclosed technology. For example, one can contact titanium sponge with a quaternary ammonium salt as described herein so as to give rise to a nanofilamentous (or subnanofilamentous) product, as described herein.
[00245] Aspect 24. The method of Aspect 23, wherein the conditions comprise a temperature of from 0 to 100 °C, to 200°C, or even to 300 °C for from about 0.5 hours to about 1, 2, 3, 4, or 5 weeks. The temperature can be constant during the time of exposure, but can also be varied, e.g., increased and/or decreased. The temperature can be, e.g., from about 0 to about 300 °C, from about 5 to about 95 °C, from about 10 to about 90 °C, from about 15 to about 85 °C, from about 20 to about 80 °C, from about 25 to about 75 °C, from about 30 to about 70 °C, from about 35 to about 65 °C, from about 40 to about 60 °C, from about 45 to about 55 °C, or even about 50 °C. Temperatures from 100 to 200 °C are also suitable. The temperature can be varied during the exposure (e.g., exposure to a first temperature and then a second temperature), but this is not a requirement. The exposure can be, e.g., according to a preprogrammed schedule that sets temperatures and/or durations of exposure. The exposure temperature can be, e.g., about 25, about 30, about 35, about 40, about 45, about 50, about 55, about 60, about 65, about 70, about 75, about 80, about 90, about 95, or even about 100 °C.
[00246] The conditions can, in some embodiments, comprise a temperature of from about 20 to about 300 °C and an exposure of from about 0.5 hours to about 2, 3, 4, or even 5 weeks. The conditions can comprise a temperature of about 100 to about 200 °C and an exposure of from about 1 hours to about 1 week. The temperature can be constant during the time of exposure, but can also be varied, e.g., increased and/or decreased. The temperature can be, e.g., from about 100 to about 200 °C, from about 105 to about 195 °C, from about 100 to about 190 °C, from about 115 to about 185 °C, from about 120 to about 180 °C, from about 25 to about 175 °C, from about 130 to about 170 °C, from about 135 to about 165 °C, from about 140 to about 160 °C, from about 145 to about 155 °C, or even about 150 °C. The temperature can be varied during the exposure (e.g., exposure to a first temperature and then a second temperature), but this is not a requirement. The exposure can be, e.g., according to a preprogrammed schedule that sets temperatures and/or durations of exposure. The exposure temperature can be, e.g., about 125, about 130, about 135, about 140, about 145, about 150, about 155, about 160, about 165, about 170, about 175, about 180, about 190, about 195. The method can be performed in a closed system, e.g., in a pressure vessel. The pressure can be atmospheric, but can also be less than atmospheric pressure or even can be greater than atmospheric pressure, e.g., a pressure of greater than 1 atmosphere (101.325 kPa) to about 10 atmospheres (1013.250 kPa).
[00247] The period of exposure (which can be termed a “reaction time”) can be, e.g., from about 1 hours to about 7 days, from about 5 hours to about 6 days, from about 15 hours to about 5 days, from about 20 hours to about 4 days, from about 24 hours to about 3 days, or even about 2 days. As but some example, the exposure can be for from 12 hours to about 72 hours, about 15 hours to about 70 hours, about 18 hours to about 64 hours, about 24 hours to about 60 hours, about 30 hours to about 55 hours, about 33 hours to about 52 hours, about 37 hours to about 48 hours, about 40 hours to about 45 hours, and all intermediate values and sub-combinations of ranges.
[00248] Aspect 25. The method of Aspect 23, comprising contacting a mono-, binary, ternary, or higher boride (which can comprise Ti) with a quaternary ammonium salt and/or base so as to give rise to a product, which product can be nanofilamentous and/or subnanofilamentous.
[00249] Aspect 26. The method of Aspect 25, wherein the binary boride comprises one or more titanium borides.
[00250] Aspect 27. The method of any one of Aspects 23-26, wherein the quaternary ammonium salt and/or base comprises an ammonium hydroxide, an ammonium halide, or any combination thereof.
[00251] Aspect 28. The method of Aspect 27, wherein the quaternary ammonium hydroxide comprises tetramethyl ammonium hydroxide (TMAOH), tetraethylammonium hydroxide (TEAOH), tetrapropylammonium hydroxide (TPAOH), tetrabutylammonium hydroxide (TBAOH), ammonium hydroxide (NTUOH), their amine derivatives, or any combination thereof.
[00252] Aspect 29. The method of Aspect 27, wherein the quaternary ammonium salt comprises a quaternary ammonium chloride, a quaternary ammonium bromide, a quaternary ammonium iodide, a quaternary ammonium fluoride, or any combination thereof. It should be understood that one can use either or both of a quaternary ammonium salt and a quaternary ammonium base.
[00253] Aspect 30. The method of any one of Aspects 23-29, further comprising filtering the product.
[00254] Aspect 31. The method of any one of Aspects 23-30, further comprising washing the product with a metal salt and/or other water-soluble metal compound.
[00255] The metal salt can be a metal halide salt, e.g., a Li halide, a Na halide, a K halide, an Rb halide, a Cs halide, a Fr halide, a Be halide, a Mg halide, a Ca halide, a Sr halide, a Ba halide, a Ra halide, a Mn halide, a Fe halide, a Ni halide, a Co halide, a Cu halide, a Zn halide, a Mo halide, aNb halide, a W halide, or any combination thereof.
[00256] Aspect 32. The method of any one of Aspects 23-31, further comprising washing the product with a metal salt and/or water-soluble metal compounds. The metal salt can optionally comprise metal sulfate, nitrate, chromate, acetate, carbonate, permanganate, or metal hydroxide, or any combination of thereof.
[00257] Aspect 33. The method of Aspect 32, wherein the metal in the salt can be essentially any metal from the periodic table. As but some non-limiting examples, the metal in the metal salt can be Li, Na, K, Cs, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Mo, Cd, Ta, or W, or any combination of thereof. A metal salt can be, e.g., LiCl, KC1, NaCl, LiF, KF, NaF, LiOH, KOH, NaOH, or any combination thereof.
[00258] Aspect 34. The method of any one of Aspects 32-33, wherein the metal salt is LiCl, KC1, NaCl, LiF, CsCl, KF, NaF, LiOH, KOH, NaOH, or any combination thereof.
[00259] Aspect 35. The method of any one of Aspects 32-33, wherein the metal salt comprises CrCb, MnCh, FeCh, FeCb, CoCh, NiCh, MoCb, FeS04, (NH4)2Fe(S04)2, CuCh, CuCl, ZnCh or any combination thereof.
[00260] Aspect 36. The method of any one of Aspects 23-35, wherein the product is a composition according to any one of Aspects 1-16.
[00261] Aspect 37. The method of any one of Aspects 23-36, wherein the nanofilamentous (and/or subnanofilamentous) product exhibits a XRD pattern that, when compared to a XRD pattern of nano- or bulk anatase, exhibit reduced (104) and (105) peaks at around 38° and about 55° two theta (2Q). As described elsewhere herein, the disclosed nanofilaments and/or subnanofilaments can, in some embodiments, exhibit a Raman spectrum that is similar to that of bulk anatase, but can differ from bulk anatase in terms of the XRD spectrum, as described herein.
[00262] Aspect 38. A method, comprising:
[00263] contacting particulate TiCh with a quaternary ammonium salt and/or base,
[00264] the contacting being performed under conditions sufficient to give rise to an anatase nanoparticulate product,
[00265] the nanoparticulate product optionally at least some nanoparticles having a diameter of from about 2 nm to about 1000 nm, optionally from about 10 to about 100 nm.
[00266] The nanoparticulate product can be further processed, e.g., by heating, by further reaction, and the like. The further processing can be performed to coarsen the product, e.g., to give rise to larger-size particles, e.g., from about 0.1 to about 0.7 pm, or from about 0.2 to about 0.5 pm.
[00267] The disclosed methods for making an anatase product of the present disclosure provide a substitute for TiCh (including pigment-grade TiCh) and also provide an improvement over existing processes for making such TiCh, in particular pigment- grade TiCh.
[00268] More specifically, to make pigment-grade TiCh at present, one begins with low-grade TiCh and then chlorinates that low-grade TiCh at a high temperature to convert the TiCh to TiCU and then oxidize the latter. The disclosed methods provide an improvement over this cumbersome existing process.
[00269] The contacting can be at from about 20 to about 80 °C, or from about 25 to about 75 °C, or from about 30 to about 70 °C, or from about 35 to about 65 °C, or from about 40 to about 60 °C, or from about 45 to about 55 °C, even about 50 °C. The contacting can be from , e.g., about 5 minutes to about 5 hours, from about 10 minutes to about 4.5 hours, from about 15 minutes to about 4 hours, from about 20 minutes to about 3.5 hours, from about 30 minutes to about 3 hours, from about 45 minutes to about 2 hours, or any combination or subrange thereof. [00270] Aspect 39. The method of Aspect 38, wherein the quaternary ammonium salt and/or base comprises an ammonium hydroxide, an ammonium halide, or any combination thereof.
[00271] Aspect 40. The method of Aspect 38, wherein the quaternary ammonium base comprises tetramethylammonium hydroxide (TMAOH), tetraethylammonium hydroxide (TEAOH), tetrapropylammonium hydroxide (TPAOH), tetrabutylammonium hydroxide (TBAOH), ammonium hydroxide (NH4OH), their amine derivatives, or any combination thereof.
[00272] Aspect 41. The method of Aspect 38, wherein the quaternary ammonium salt comprises a quaternary ammonium chloride, a quaternary ammonium bromide, a quaternary ammonium iodide, a quaternary ammonium fluoride, or any combination thereof. As described elsewhere herein, one can use either or both of a quaternary ammonium salt and a quaternary ammonium base.
[00273] Aspect 42. The method of any one of Aspects 38-41, further comprising filtering the product.
[00274] Aspect 43. A composition, comprising a population of anatase nanoparticles made according to any one of Aspects 38-42. Such nanoparticles can be in the size range of from about 200 nm to about 600 nm, e.g., from about 200 nm to about 600 nm, from about 225 to about 575 nm, from about 250 to about 550 nm, from about 275 nm to about 525 nm, from about 300 to about 500 nm, from about 325 to about 475 nm, from about 350 to about 450 nm, from about 375 to about 425 nm, or even about 400 nm.
[00275] Aspect 44. A method, comprising replacing T1O2 with a population of anatase nanoparticles made according to any one of Aspects 38-42. As an example, one can formulate a pigment normally made with traditional T1O2 by replacing the traditional T1O2 with anatase nanoparticles according to the present disclosure, e.g., according to any one of Aspects 38-42.
[00276] Aspect 45. A method, comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non- water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting optionally performed while shaking, and the contacting being performed under conditions sufficient to give rise to mesoporous particles.
[00277] Aspect 46. A method, comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non- water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting optionally performed while shaking, the contacting being followed by washing with at least one salt and performed under conditions sufficient to give rise to mesoporous particles.
[00278] Aspect 47. A method, comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non- water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting performed while shaking and at a temperature of from about 50 to about 95 °C, followed by washing with LiCl to give rise to mesoporous particles.
[00279] Aspect 48. A composition comprising mesoporous particles made according to any one of claims 45-47.
[00280] The mesoporous particles can exhibit a XRD pattern that, when compared to a XRD pattern of nano- or bulk anatase, exhibit reduced (104) and (105) peaks at around 38° and about 55° two theta (2Q). The disclosed mesoporous particles can, in some embodiments, exhibit a Raman spectrum that is quite similar to that of bulk anatase, but can also differ from bulk anatase in terms of the XRD spectrum, as described herein. [00281] Aspect 49. A composition, comprising mesoporous particles, wherein the mesoporous particles comprise titanium and wherein the mesoporous particles exhibit a XRD pattern that, when compared to a XRD pattern of nano- or bulk anatase, exhibit reduced (104) and (105) peaks at around 38° and about 55° two theta (2Q). The disclosed mesoporous particles can, in some embodiments, exhibit a Raman spectrum that is quite similar to that of bulk anatase, but can also differ from bulk anatase in terms of the XRD spectrum, as described herein.
[00282] Aspect 50. The composition according to any one of claims 48-49, further comprising a therapeutic.
[00283] Aspect 51. A method, comprising effecting delivery of a therapeutic to a subject, the therapeutic being comprised in a composition according to any one of claims 48-49.
[00284] Aspect 52. An electrode, the electrode comprising a composition according to any one of claims 48-49.
[00285] Aspect 53. A device, the device comprising a composition according to any one of claims 48-49.
[00286] Aspect 54. The device of claim 52, wherein the device is an energy storage device.
[00287] Aspect 55. A method, the method comprising operating the device of any one of claims 52-53.

Claims

What is Claimed:
1. A composition, comprising: a plurality of metal oxide subnanofilaments and/or nanofilaments, and optionally an amount of carbon.
2. The composition of claim 1, wherein at least some of the nanofilaments and/or subnanofilaments have a width in the range of from about 3 to about 50 A.
3. The composition of claim 2, wherein at least some of the nanofilaments and/or subnanofilaments have an average width in the range of from about 7 to about 20
A.
4. The composition of claim 1, wherein the nanofilaments and/or subnanofilaments define a non-circular cross-section.
5. The composition of claim 4, wherein the nanofilaments and/or subnanofilaments define a cross-sectional aspect ratio of from greater than 1 to about 10.
6. The composition of claim 5, wherein the nanofilaments and/or subnanofilaments define a cross-sectional aspect ratio of from about 2 to about 5.
7. The composition of claim 1, wherein the nanofilaments and/or subnanofilaments have an average cross-sectional area in the range of from about 10 to about 100 A2.
8. The composition of claim 1, wherein at least some of the nanofilaments and/or subnanofilaments have a length in the range of from 1 nm to about 25 pm.
9. The composition of claim 8, wherein at least some of the nanofilaments and/or subnanofilaments have a length in the range of from 1 nm to about 1 pm.
10. The composition of claim 1, wherein the nanofilaments and/or subnanofilaments are comprised in a plurality of flakes.
11. The composition of claim 7, wherein at least some of the plurality of the nanofilaments and/or subnanofilaments he in a common plane
12. The composition of any one of claims 1-11, further comprising a pharmaceutically acceptable carrier.
13. The composition of claim 1, further comprising one or more materials that are fatal to cancer cells.
14. The composition of claim 1, further comprising a binder.
15. The composition of claim 14, wherein the binder comprises a polymer.
16. The composition of claim 1, wherein the nanofilaments exhibit a XRD pattern that, when compared to a XRD pattern of bulk or nano anatase, exhibit reduced (104) and (105) peaks at around 38° and about 55° two theta.
17. A device, the device comprising a composition according to claim 1.
18. The device of claim 17, wherein the device comprises an electrode.
19. The device of claim 17, wherein the device is characterized as an energy storage device.
20. The device of claim 18, wherein the electrode comprises the composition according to claim 1.
21. The device of claim 17, wherein the device comprises a dispenser, the dispenser having disposed therein the composition according to claim 1.
22. A method, comprising operating a device according to claim 17.
23. A method, comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non-water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting being performed under conditions sufficient to give rise to a nanofilamentous product.
24. The method of claim 23, wherein the conditions comprise a temperature of from 0 to 100 °C for from about 5 hours to about 1 week.
25. The method of claim 23, comprising contacting a binary, ternary, or higher boride with a quaternary ammonium salt and/or base so as to give rise to a nanofilamentous product.
26. The method of claim 25, wherein the binary boride comprises one or more titanium borides.
27. The method of claim 23, wherein the quaternary ammonium salt and/or base comprises an ammonium hydroxide, an ammonium halide, or any combination thereof.
28. The method of claim 27, wherein the quaternary ammonium hydroxide comprises tetramethylammonium hydroxide (TMAOH), tetraethylammonium hydroxide (TEAOH), tetrapropylammonium hydroxide (TPAOH), tetrabutylammonium hydroxide (TBAOH), ammonium hydroxide (NH4OH), their amine derivatives, or any combination thereof.
29. The method of claim 27, wherein the quaternary ammonium salt comprises a quaternary ammonium chloride, a quaternary ammonium bromide, a quaternary ammonium iodide, a quaternary ammonium fluoride, or any combination thereof.
30. The method of claim 23, further comprising filtering the product.
31. The method of claim 23, further comprising washing the product with a metal salt and/or other water-soluble metal compounds.
32. The method of claim 23, further comprising washing the product with a metal salt and/or water-soluble metal compounds, the metal salt optionally comprising metal sulfate, nitrate, chromate, acetate, carbonate, permanganate, or metal hydroxide, or any combination of thereof.
33. The method of claim 32, wherein a metal in the metal salt comprises Li, Na, K, Cs, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Mo, Cd, Ta, or W, or any combination of thereof.
34. The method of claim 32, wherein the metal salt comprises LiCl, KC1, NaCl, CsCl, LiF, KF, NaF, LiOH, KOH, NaOH, or any combination thereof.
35. The method of claim 32, wherein the metal salt comprises CrCh. MnCh. FeCh. FeCb, CoCk , NiCk, MoCL, FeSCri, (NH4)2Fe(S04)2, CuCk, CuCl, ZnCk or any combination thereof.
36. The method of claim 23, wherein the product is a composition according to claim 1
37. The method of claim 23, wherein the nanofilamentous product exhibits a two- dimensional XRD pattern that, when compared to a XRD pattern of nano or bulk anatase, exhibit reduced (104) and (105) peaks at around 38° and about 55° two theta.
38. A method, comprising: contacting particulate Ti02 with a quaternary ammonium salt and/or base, the contacting being performed under conditions sufficient to give rise to an anatase nanoparticulate product, the nanoparticulate product optionally at least some nanoparticles having a diameter of from about 2 nm to about 1000 nm, optionally from about 10 to about 100 nm.
39. The method of claim 38, wherein the quaternary ammonium salt and/or base comprise an ammonium hydroxide, an ammonium halide, or any combination thereof.
40. The method of claim 38, wherein the quaternary ammonium base comprises tetramethylammonium hydroxide (TMAOH), tetraethylammonium hydroxide (TEAOH), tetrapropylammonium hydroxide (TPAOH), tetrabutylammonium hydroxide (TBAOH), ammonium hydroxide (NTUOH), their amine derivatives, or any combination thereof.
41. The method of claim 38, wherein the quaternary ammonium salt comprises a quaternary ammonium chloride, a quaternary ammonium bromide, a quaternary ammonium iodide, a quaternary ammonium fluoride, or any combination thereof together with a base.
42. The method of claim 38, further comprising filtering the product.
43. A composition, comprising a population of anatase nanoparticles made according to claim 38.
44. A method, comprising replacing TiCh with a population of anatase nanoparticles made according to claim 38.
45. A method, comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non-water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting optionally performed while shaking, and the contacting being performed under conditions sufficient to give rise to mesoporous particles.
46. A method, comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non-water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting optionally performed while shaking, the contacting being followed by washing with at least one salt and performed under conditions sufficient to give rise to mesoporous particles.
47. A method, comprising: contacting a mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal with a quaternary ammonium salt and/or base, the mono-, binary, ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide, or titanium metal optionally being non-water-soluble, the non-water soluble binary, or ternary, or higher carbide, nitride, boride, phosphide, aluminide, or silicide optionally comprising a transition metal, the transition metal optionally comprising titanium, the contacting performed while shaking and at a temperature of from about 50 to about 95 °C, followed by washing with LiCl to give rise to mesoporous particles
48. A composition comprising mesoporous particles made according to any one of claims 45-47.
49. A composition, comprising mesoporous particles, wherein the mesoporous particles comprise titanium and wherein the mesoporous particles exhibit a XRD pattern that, when compared to a XRD pattern of nano- or bulk anatase, exhibit reduced (104) and (105) peaks at around 38° and about 55° two theta (2Q).
50. A composition according to claim 48, further comprising a therapeutic.
51. A composition according to claim 49, further comprising a therapeutic.
52. A method, comprising effecting delivery of a therapeutic to a subject, the therapeutic comprised in a composition according to claim 48.
53. A method, comprising effecting delivery of a therapeutic to a subject, the therapeutic comprised in a composition according to claim 49.
54. An electrode, the electrode comprising a composition according to claim 48.
55. An electrode, the electrode comprising a composition according to claim 49.
56. A device, the device comprising a composition according to claim 48.
57. A device, the device comprising a composition according to claim 49.
58. The device of claim 56 or claim 57, wherein the device is an energy storage device.
59. A method, the method comprising operating the device of claim 57.
60. A method, the method comprising operating the device of claim 58.
PCT/US2022/070644 2021-02-11 2022-02-11 Bottom-up, scalable synthesis of oxide-based sub-nano and nanofilaments and nanofilament-based two-dimensional flakes and mesoporous powders WO2022174264A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2023548178A JP2024507122A (en) 2021-02-11 2022-02-11 Bottom-up and scalable synthesis of oxide-based subnano and nanofilaments, nanofilament-based two-dimensional flakes and mesoporous powders
EP22753568.9A EP4291240A1 (en) 2021-02-11 2022-02-11 Bottom-up, scalable synthesis of oxide-based sub-nano and nanofilaments and nanofilament-based two-dimensional flakes and mesoporous powders
CN202280021775.XA CN117042802A (en) 2021-02-11 2022-02-11 Oxide-based sub-nanowires and bottom-up expandable synthesis of nanowires and two-dimensional flakes and mesoporous powders based on nanowires
US18/448,593 US20240097109A1 (en) 2021-02-11 2023-08-11 Bottom-Up, Scalable Synthesis Of Oxide-Based Sub-Nano And Nanofilaments And Nanofilament-Based Two-Dimensional Flakes And Mesoporous Powders

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
US202163148348P 2021-02-11 2021-02-11
US63/148,348 2021-02-11
US202163167197P 2021-03-29 2021-03-29
US63/167,197 2021-03-29
US202163171293P 2021-04-06 2021-04-06
US63/171,293 2021-04-06
US202163275631P 2021-11-04 2021-11-04
US63/275,631 2021-11-04

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US18/448,593 Continuation-In-Part US20240097109A1 (en) 2021-02-11 2023-08-11 Bottom-Up, Scalable Synthesis Of Oxide-Based Sub-Nano And Nanofilaments And Nanofilament-Based Two-Dimensional Flakes And Mesoporous Powders

Publications (1)

Publication Number Publication Date
WO2022174264A1 true WO2022174264A1 (en) 2022-08-18

Family

ID=82838001

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2022/070644 WO2022174264A1 (en) 2021-02-11 2022-02-11 Bottom-up, scalable synthesis of oxide-based sub-nano and nanofilaments and nanofilament-based two-dimensional flakes and mesoporous powders

Country Status (3)

Country Link
EP (1) EP4291240A1 (en)
JP (1) JP2024507122A (en)
WO (1) WO2022174264A1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150262763A1 (en) * 2012-12-12 2015-09-17 Samsung Fine Chemicals Co., Ltd Supercapacitor electrode material having combined porous titanium oxide and carbon-based material, and method for manufacturing same
CN108245682A (en) * 2018-02-11 2018-07-06 中国人民解放军第二军医大学 The mesoporous MXene nanometer sheets pharmaceutical carrier of acidity, photothermal response type and preparation method
US20190076821A1 (en) * 2013-09-23 2019-03-14 Huntsman P&A Uk Limited Titania particles and a process for their production
WO2019126031A1 (en) * 2017-12-22 2019-06-27 Drexel University Crumpled mesoporous mxene powders synthesized by acid-, base-, or salt-induced crumpling

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150262763A1 (en) * 2012-12-12 2015-09-17 Samsung Fine Chemicals Co., Ltd Supercapacitor electrode material having combined porous titanium oxide and carbon-based material, and method for manufacturing same
US20190076821A1 (en) * 2013-09-23 2019-03-14 Huntsman P&A Uk Limited Titania particles and a process for their production
WO2019126031A1 (en) * 2017-12-22 2019-06-27 Drexel University Crumpled mesoporous mxene powders synthesized by acid-, base-, or salt-induced crumpling
CN108245682A (en) * 2018-02-11 2018-07-06 中国人民解放军第二军医大学 The mesoporous MXene nanometer sheets pharmaceutical carrier of acidity, photothermal response type and preparation method

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
GHIDIU MICHAEL, HALIM JOSEPH, KOTA SANKALP, BISH DAVID, GOGOTSI YURY, BARSOUM MICHEL W.: "Ion-Exchange and Cation Solvation Reactions in Ti3C2 MXene", CHEMISTRY OF MATERIALS, vol. 28, no. 10, 1 January 2016 (2016-01-01), pages 3507 - 3514, XP055963098, DOI: 10.1021/acs.chemmater.6b01275 *
HANTANASIRISAKUL KANIT, ALHABEB MOHAMED, LIPATOV ALEXEY, MALESKI KATHLEEN, ANASORI BABAK, SALLES POL, IEOSAKULRAT CHANOKNAN, PAKAW: "Effects of Synthesis and Processing on Optoelectronic Properties of Titanium Carbonitride MXene", CHEMISTRY OF MATERIALS, vol. 31, no. 8, 23 April 2019 (2019-04-23), pages 2941 - 2951, XP055962916, DOI: 10.1021/acs.chemmater.9b00401 *
HONG MIN-HEE, PARK CHANG-SUN, PARK HYUNG-HO: "Synthesis of Au nanoparticle-incorporated mesoporous Ti02 composite thin films and their electrical properties", JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, vol. 122, no. 11, 1 November 2014 (2014-11-01), pages 959 - 962, XP055962896, DOI: 10.2109/jcersj2.122.959 *
THOMAS, L: "How Thin is a Thin Film?", AZO MATERIALS, 7 December 2018 (2018-12-07), pages 1 - 7, XP055963104, Retrieved from the Internet <URL:Https://www.azom.com/article.aspx?ArticleID=17334> *
VEGA, MPB ET AL.: "Visible light photocatalytic activity of sol-gel Ni-doped Ti02 on parsanilic acid degradation", JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY, vol. 85, 31 January 2016 (2016-01-31), pages 723 - 731, XP036452062, DOI: 10.1007/s10971-018-4579-0 *
ZHANG NING, HONG YU, YAZDANPARAST SANAZ, ASLE ZAEEM MOHSEN: "Superior structural, elastic and electronic properties of 2D titanium nitride MXenes over carbide MXenes: A comprehensive first principles study", 2D MATERIALS, vol. 5, no. 4, June 2018 (2018-06-01), pages 1 - 43, XP081107016, DOI: 10.1088/2053-1583/aacfb3 *

Also Published As

Publication number Publication date
JP2024507122A (en) 2024-02-16
EP4291240A1 (en) 2023-12-20

Similar Documents

Publication Publication Date Title
Luo et al. A three-dimensional self-assembled SnS 2-nano-dots@ graphene hybrid aerogel as an efficient polysulfide reservoir for high-performance lithium–sulfur batteries
Chen et al. Co 9 S 8 embedded into N/S doped carbon composites: in situ derivation from a sulfonate-based metal–organic framework and its electrochemical properties
Badr et al. Bottom-up, scalable synthesis of anatase nanofilament-based two-dimensional titanium carbo-oxide flakes
JP6987764B2 (en) Lithium nickelate positive electrode active material particle powder and its manufacturing method, and non-aqueous electrolyte secondary battery
Pei et al. Controlled synthesis of hollow C@ TiO 2@ MoS 2 hierarchical nanospheres for high-performance lithium-ion batteries
Li et al. Mesoporous quasi-single-crystalline NiCo 2 O 4 superlattice nanoribbons with optimizable lithium storage properties
Wu et al. Zn–Fe–ZIF-derived porous ZnFe2O4/C@ NCNT nanocomposites as anodes for lithium-ion batteries
Hu et al. ε-MnO 2 nanostructures directly grown on Ni foam: a cathode catalyst for rechargeable Li–O 2 batteries
Li et al. Constructing a novel strategy for carbon-doped TiO 2 multiple-phase nanocomposites toward superior electrochemical performance for lithium ion batteries and the hydrogen evolution reaction
Chen et al. Unusual rutileTiO 2 nanosheets with exposed (001) facets
Permana et al. Template-free synthesis of hierarchical porous anatase TiO2 microspheres with carbon coating and their electrochemical properties
Kim et al. Coaxial-nanostructured MnFe 2 O 4 nanoparticles on polydopamine-coated MWCNT for anode materials in rechargeable batteries
Di Lupo et al. Mesoporous TiO2 nanocrystals produced by a fast hydrolytic process as high-rate long-lasting Li-ion battery anodes
KR20110007112A (en) Lithium iron phosphate powder manufacturing method, olivine structured lithium iron phosphate powder, cathode sheet using said lithium iron phosphate powder, and non-aqueous solvent secondary battery
Cui et al. Reaction pathway and wiring network dependent Li/Na storage of micro-sized conversion anode with mesoporosity and metallic conductivity
Sada et al. P3-type layered K 0.48 Mn 0.4 Co 0.6 O 2: a novel cathode material for potassium-ion batteries
Yang et al. Li 4 Ti 5 O 12–TiO 2/MoO 2 nanoclusters-embedded into carbon nanosheets core/shell porous superstructures boost lithium ion storage
Zhu et al. Synthesis and electrochemical performance of Li 4 Ti 5 O 12/TiO 2/C nanocrystallines for high-rate lithium ion batteries
Qiao et al. Surface modification of MoO x S y on porous TiO 2 nanospheres as an anode material with highly reversible and ultra-fast lithium storage properties
Wang et al. Synergic antimony–niobium pentoxide nanomeshes for high-rate sodium storage
Yuvaraj et al. Synthesis and electrochemical performance of Co 2 TiO 4 and its core–shell structure of Co 2 TiO 4@ C as negative electrodes for Li-ion batteries
Xing et al. Co 2+ x Ti 1− x O 4 nano-octahedra as high performance anodes for lithium-ion batteries
Hwang et al. Facile synthesis of crumpled nitrogen-doped carbon/molybdenum disulfide hybrid sheets as high-rate anodes for lithium-ion batteries
Yin et al. Novel 2D/2D 1T-MoS 2/Ti 3 C 2 T z heterostructures for high-voltage symmetric supercapacitors
Kumari et al. An ionic liquid synthesis route for mixed-phase sodium titanate (Na 2 Ti 3 O 7 and Na 2 Ti 6 O 13) rods as an anode for sodium-ion batteries

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22753568

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2023548178

Country of ref document: JP

WWE Wipo information: entry into national phase

Ref document number: 2022753568

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 202280021775.X

Country of ref document: CN

ENP Entry into the national phase

Ref document number: 2022753568

Country of ref document: EP

Effective date: 20230911