CA3240144A1 - Process for producing nanoflakes from g-c3n4/metal composite material - Google Patents

Process for producing nanoflakes from g-c3n4/metal composite material Download PDF

Info

Publication number
CA3240144A1
CA3240144A1 CA3240144A CA3240144A CA3240144A1 CA 3240144 A1 CA3240144 A1 CA 3240144A1 CA 3240144 A CA3240144 A CA 3240144A CA 3240144 A CA3240144 A CA 3240144A CA 3240144 A1 CA3240144 A1 CA 3240144A1
Authority
CA
Canada
Prior art keywords
composite material
metal composite
nanoflakes
iron
optionally
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
CA3240144A
Other languages
French (fr)
Inventor
Merkur SMAJLAJ
Michael Renz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hydrosolid GmbH
Original Assignee
Hydrosolid GmbH
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 Hydrosolid GmbH filed Critical Hydrosolid GmbH
Publication of CA3240144A1 publication Critical patent/CA3240144A1/en
Pending legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B21/00—Nitrogen; Compounds thereof
    • C01B21/082—Compounds containing nitrogen and non-metals and optionally metals
    • C01B21/0828—Carbonitrides or oxycarbonitrides of metals, boron or silicon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
    • B01J27/24—Nitrogen compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
    • B01J21/18—Carbon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74—Iron group metals
    • B01J23/745—Iron
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • B01J35/39—Photocatalytic properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/40—Catalysts, in general, characterised by their form or physical properties characterised by dimensions, e.g. grain size
    • B01J35/45—Nanoparticles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/50—Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/08—Heat treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/34—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation
    • B01J37/341—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation making use of electric or magnetic fields, wave energy or particle radiation
    • B01J37/343—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation making use of electric or magnetic fields, wave energy or particle radiation of ultrasonic wave energy
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B25/00—Phosphorus; Compounds thereof
    • C01B25/16—Oxyacids of phosphorus; Salts thereof
    • C01B25/26—Phosphates
    • C01B25/37—Phosphates of heavy metals
    • C01B25/375—Phosphates of heavy metals of iron
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen; Reversible storage of hydrogen
    • C01B3/0005—Reversible storage of hydrogen, e.g. by hydrogen getters or electrodes
    • C01B3/001—Reversible storage of hydrogen, e.g. by hydrogen getters or electrodes characterised by the uptaking media; Treatment thereof
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen; Reversible storage of hydrogen
    • C01B3/0005—Reversible storage of hydrogen, e.g. by hydrogen getters or electrodes
    • C01B3/001—Reversible storage of hydrogen, e.g. by hydrogen getters or electrodes characterised by the uptaking media; Treatment thereof
    • C01B3/0018—Inorganic elements or compounds, e.g. oxides, nitrides, borohydrides or zeolites; Solutions thereof
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen; Reversible storage of hydrogen
    • C01B3/0005—Reversible storage of hydrogen, e.g. by hydrogen getters or electrodes
    • C01B3/001—Reversible storage of hydrogen, e.g. by hydrogen getters or electrodes characterised by the uptaking media; Treatment thereof
    • C01B3/0018—Inorganic elements or compounds, e.g. oxides, nitrides, borohydrides or zeolites; Solutions thereof
    • C01B3/0026—Metals or metal hydrides
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen; Reversible storage of hydrogen
    • C01B3/0005—Reversible storage of hydrogen, e.g. by hydrogen getters or electrodes
    • C01B3/001—Reversible storage of hydrogen, e.g. by hydrogen getters or electrodes characterised by the uptaking media; Treatment thereof
    • C01B3/0078—Composite solid storage media, e.g. mixtures of polymers and metal hydrides, coated solid compounds or structurally heterogeneous solid compounds
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/02—Electrodes; Manufacture thereof not otherwise provided for characterised by shape or form
    • C25B11/037—Electrodes made of particles
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/075—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of a single catalytic element or catalytic compound
    • C25B11/087—Photocatalytic compound
    • 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
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/90—Selection of catalytic material
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
    • 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
    • Y02E60/30—Hydrogen technology
    • Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Electrochemistry (AREA)
  • Metallurgy (AREA)
  • Nanotechnology (AREA)
  • Optics & Photonics (AREA)
  • Thermal Sciences (AREA)
  • Toxicology (AREA)
  • Plasma & Fusion (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Composite Materials (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • General Chemical & Material Sciences (AREA)
  • Catalysts (AREA)
  • Powder Metallurgy (AREA)
  • Hydrogen, Water And Hydrids (AREA)
  • Electrodes For Compound Or Non-Metal Manufacture (AREA)
  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)

Abstract

The present invention relates to a process for producing g-C3N4/metal composite material nanoflakes comprising the steps of: (a) providing a starting material comprising or consisting of FePO4, urea and polyacrylonitrile, wherein the starting material is in the form of powder having particles having an average particle size of less than 100 nm, (b) dispersing the starting material in a solvent, wherein the solvent is water, (c) removing the solvent to form a premixture containing the starting material, (d) heating the premixture and pyrolyzing the premixture at a pyrolysis temperature between 200°C and 700°C, preferably between 400°C and 600°C, to form a bulk-g-C3N4/metal composite material, (e) treating the bulk g-C3N4/metal composite material with ultrasound to form g-C3N/4/metal composite material nanoflakes.

Description

Method for producing nanoflakes from g-C3N4/metal composite material The present invention relates to a method for producing nanoflakes from a g-C3N4/metal composite material according to the features of the independent patent claim 1. The invention further relates to nanoflakes obtainable by such a method, to a hydrogen storage material and to a photocatalyst, a photoelectrocatalyst and an electrocatalyst, which contain nanoflakes according to the invention.
Graphitic carbon nitride, also referred to as g-C3N4, is a polymer material that, according to the state of the art, is used in various fields of application, for example for heterogeneous catalysis applications or as a storage material for molecular hydrogen.
Pure g-C3N4 is a metal-free compound whose properties are customized and improved by the formation of composite materials with metals or metal compounds.
Materials based on g-C3N4 are already known in the state of the art. The paper "Facile Production of a Fenton-Like Photocatalyst by Two-Step Calcination with a Broad pH
Adaptability" by Siyang Ji et al. (nanomaterials, 2020) describes g-C3N4 nanoflakes, in which iron is incorporated into the g-C3N4. CN 104437643 A describes an impregnation of g-C3N4 with ferrous substances. CN 110479345 A describes g-C3N4 quantum dots carried on Fe-oxide flakes. CN 110429277 A describes a sulphur-doped g-C3N4 material without going into detail about the exact properties of the iron it contains. The paper "Facile synthesis of graphitic carbon nitride/chitosam/Au nanocomposite:
A
catalyst for electrochemical hydrogen evolution" by Atefeh Nasri et al.
(International J ournal of Biological Macromolecules, 2020) describes a g-C3N4 gold nanocomposite.
CN 112156662 A discloses nanofibres.
However, the performance characteristics of known g-C3N4 metal composite materials are insufficient, particularly for the storage of hydrogen and the photocatalytic production of hydrogen and oxygen from water. In particular, the storage capacity for hydrogen and/or the achievable hydrogen production rate are factors of known g-C3N4/metal composites that require improvement.
It is therefore an object of the present invention to overcome the disadvantages of known g-C3N4/metal composite materials. In particular, one object of the present invention is to provide a g-C3N4/metal composite material, which is improved with respect to at least one of the following performance characteristics: storage capacity for hydrogen, adsorption capacity for hydrogen, hydrogen production rate, achievable electrical current density in photoelectrocatalysis and electrolysis of water.
In the context of the present invention, it was surprisingly found that these and other objects can be achieved in particular by a composite material produced by a method according to the invention.
The present invention relates to a method for producing g-C3N4/metal composite material nanoflakes comprising several steps.
Optionally, a step (a) having the following features is provided: providing a starting material comprising or consisting of an iron compound, a g-C3N4 precursor material and a polymer. The iron compound may be iron(III) phosphate. The g-C3N4 precursor material may be urea (CH4N20). The polymer may be polyacrylonitrile. In particular, the starting material is a powder whose particles have an average particle size of less than 100 nm.
It was found that the use of polyacrylonitrile in the starting material allows nanoflakes with particularly favourable properties to be obtained. Without being limited to this theory, it is assumed that the polyacrylonitrile forms a template that significantly influences the geometric parameters, in particular length, width, shape, and orientation, of the nanoflakes produced.
Optionally, a further advantageous technical effect of polyacrylonitrile is that cyclisation of the polyacrylonitrile may take place as part of the process, whereby a conductor polymer is formed, which provides the g-C3N4 material with particular stability, in particular with regard to chemical, thermal and mechanical properties. For example, the use of polyacrylonitrile can provide the composite material with improved flame, fire and heat resistance, which is particularly advantageous in applications involving hydrogen, as the potential formation of oxyhydrogen gas mixtures and burning hydrogen gas cannot cause the composite material to ignite.

Optionally, a step (b) having the following features is provided: dispersing the starting material in a solvent, wherein the solvent is in particular water. Optionally, the water has a boiling temperature in step (b). Optionally, this step results in incomplete dissolution of the starting material in the solvent.
A better dispersion, in particular achievable by the smallest possible diameter of the particles of the starting material, improves the subsequent reaction to g-C3N4, for example with regard to yield and kinetics.
Optionally, a step (c) having the following features is provided: removing the solvent to form a premix containing the starting material.
Optionally, a step (d) having the following features is provided: heating the premix obtained in step (c) and pyrolyzing the premix at a pyrolosis temperature between 200 C and 700 C, preferably between 400 C and 600 C to form a bulk-g-C3N4/metal composite material.
"Bulk-g-C3N4/metal composite material" in the context of the present invention refers in particular to a material with a coherent, layered structure in which optionally a plurality of layers is superimposed.
Optionally, a step (d) having the following features is provided: Treating the bulk-g-C3N4/metal composite material with ultrasound to form g-C3N4/metal composite material nanoflakes.
The ultrasound treatment causes in particular an exfoliation of the g-C3N4/rnetal composite material, wherein nanoflakes are formed from the bulk material.
Optionally, the layered structure of the bulk material is fractured, whereby the nanoflakes are formed. Another advantageous effect of ultrasound treatment may be a better distribution of the metal between the g-C3N4 layers, which then may optionally act as stabilising spacers.

Optionally, the ultrasound used for the treatment in step (e) has a frequency between 20 kHz and 100 kHz. Optionally, the energy input by the ultrasound in step (d) is at least 0.25 W per g of the bulk g-C3N4 /metal composite material.
In the context of the present invention, "nanoflakes" refer in particular to particles that have an external dimension precisely in the nanoscale range, i.e. between 1 nm and 100 nm.
The nanoflakes produced by the method according to the invention or the nanoflakes according to the invention are in particular nanoporous, i.e. they have pores with a dimension in the sub-100 nm range. The nanoporosity is achieved in particular by dispersion and optional grinding and by ultrasound treatment in step (b).
Optionally, it is provided that the amount of the iron compound in step (a) is between 1.0 wt% and 20 wt% with respect to the total amount of the starting material.
Optionally, it is provided that the dispersion in step (b) is carried out at a temperature between 80 C and 100 C, preferably between 90 C and 100 C. This allows the starting material to partially dissolve, which optionally improves the completeness of the reaction to g-C3N4.
Optionally, it is provided that the dispersion in step (b) is carried out using ultrasound treatment. For example, the treatment may be carried out using an ultrasound rod, which is inserted into the dispersion. Optionally, the ultrasound used for treatment in step (b) has a frequency between 20 kHz and 100 kHz. Optionally, the energy input by the ultrasound in step (d) is at least 0.25 W per ml of the dispersion.
Improved dispersion may be achieved by ultrasound treatment, which optionally improves the completeness of the reaction to g-C3N4.
Optionally, the dispersion in step (b) takes at least 1 hour, in particular approximately 2 hours.

Optionally, it is provided that the heating rate during heating to the pyrolysis temperature in step (d) is greater than or equal to 5 C/min.
Optionally, it is provided that the pyrolysis temperature in step (d) is approximately 450 C. As a result, iron(III) phosphate can be obtained in the layers of the produced g-C3N4/metal composite material, when iron(III) phosphate is used in the starting material.
Optionally, it is provided that the pyrolysis temperature in step (d) is approximately 550 C. As a result, iron(III) oxide can be obtained in the layers of the produced g-C3N4/metal composite material, when iron(III) phosphate is used in the starting material.
Optionally, the pyrolysis in step (d) takes at least 4 hours, in particular approximately 5 hours.
Optionally, it is provided that the following further step is provided after step (d):
reducing the iron contained in the g-C3N4/metal composite material.
Optionally, the reduction is achieved by treating the composite material with hydrogen.
Depending on the extent of the reduction, the iron may be converted into iron (II) ions or elemental iron.
Optionally, it is provided that a further metal compound is added in step (a), wherein the further metal compound is selected from an aluminium, lithium, magnesium, titanium, nickel, platinum, palladium and vanadium compound or any mixture of these compounds.
The specific properties of the composite material may be customized by adding a further metal compound.
Optionally, it is provided that the amount of the further metal compound in step (a) is between 0.5 wt% and 5.0 wt%, preferably about 1.0 wt%, with respect to the total amount of the starting material.

Optionally, it is provided that the pyrolysis in step (d) takes place in an inert gas atmosphere, in particular in a nitrogen atmosphere. This prevents oxidation of the components.
Optionally, it is provided that in step (a) the components of the starting material are ground, optionally in a ball mill, in order to achieve a particle size of less than 100 nm.
It was found that g-C3N4/metal composite nanoflakes can also be obtained by an alternative method involving several steps:
Optionally, a step (a') having the following features is provided: providing g-C3N4 by pyrolysis of a mixture of a g-C3N4 precursor material and a polymer at a pyrolysis temperature between 200 C and 700 C, preferably between 400 C and 600 C. The g-C3N4 precursor material is in particular urea. The polymer is in particular polyacrylonitrile. Preferably, the mixture is a powder having particles of an average particle size of less than 100 nm.
Optionally, the temperature during pyrolysis and step (a') is approximately 500 .
Optionally, in step (a') the mixture is heated to the pyrolysis temperature at a heating rate of approximately 5 C/min. Optionally, the pyrolysis in step (a') takes at least 4 hour, in particular approximately 5 hours.
Optionally, a step (ID') having the following features is provided: mixing the g-C3N4 obtained in step (a') with an iron compound, wherein the iron compound is selected from iron oxide, iron sulphide, iron phosphide, iron nitride or any mixture thereof, to obtain a premix. In the context of the present invention, it was found that by using iron oxide, iron sulphide, iron phosphide or iron nitride as the iron compound, analogous results to those obtained with iron(III) phosphate can only be obtained if already prepared g-C3N4 is provided. Optionally, only a formation of g-C3N4 clusters around the iron compounds would otherwise take place, whereby no material according to the invention could be obtained.

Optionally, a step (e) having the following features is provided: grinding the premix obtained in step (b') to a particle size of less than 100 nm. Optionally, this may be achieved by ball milling.
Optionally, a step (d') having the following features is provided: treatment of the ground premix at a temperature between 400 C and 600 C to form g-C3N4/metal composite nanoflakes.
In particular, the temperature in step (d') is about 550 C, whereby an iron(III) oxide composite material can be obtained.
Optionally, the treatment in step (d') causes the nanoflakes to straighten and defects to heal.
Optionally, step (d') is carried out in an inert gas atmosphere, in particular in a nitrogen atmosphere.
The two methods both deliver g-C3N4/metal composite material nanoflakes as the end product, which have comparable properties. The methods can therefore be understood as alternative methods.
Optionally, the invention also relates to nanoflakes obtained and/or obtainable by a method according to the invention. The method steps provide the nanoflakes with special properties that distinguish them from nanoflakes known in the prior art. In particular, by using the method according to the invention, a composite material structure is created which allows a particularly homogeneous distribution of iron on the surface of g-C3N4 flakes.
Optionally, it is provided that the composite material comprises pores, wherein the pores have an average pore size of less than 100 nm.

Optionally, it is provided that g-C3N4-nanoflakes are provided, on the surface of which iron and/or the iron compound is carried, wherein the iron and/or the iron compound is presented in particulate form with a particle diameter of less than 100 nm.
Optionally, the invention also relates to a hydrogen storage material containing or consisting of g-C3N4/metal composite nanoflakes according to the invention.
Optionally, the invention relates to the use of g-C3N4/metal composite nanoflakes according to the invention as hydrogen storage material.
Optionally, the invention relates to a method for storing hydrogen comprising loading g-C3N4/metal composite material nanoflakes according to the invention with hydrogen gas. Optionally, loading takes place at a pressure of greater than 10 bar, preferably less than 25 bar.
Optionally, desorption of the hydrogen is achieved by heating the loaded composite material, for example to a temperature between 60 C and 100 C.
The influence of an electric field is able to enhance the loading. The voltage of the electric field is optionally more than 1000 V.
Optionally, the invention also relates to a photocatalyst containing or consisting of g-C3N4/metal composite material nanoflakes according to the invention.
Optionally, the invention relates to the use of g-C3N4/metal composite material nanoflakes according to the invention as photocatalyst.
Optionally, the invention also relates to a photoelectrocatalyst containing or consisting of g-C3N4/rnetal composite material nanoflakes according to the invention.
Optionally, the invention relates to the use of g-C3N4/metal composite material nanoflakes according to the invention as photoelectrocatalyst.
Optionally, the invention further relates to an electrocatalyst containing or consisting of g-C3N4/metal composite material nanoflakes according to the invention.
Optionally, the invention relates to the use of g-C3N4/metal composite material nanoflakes according to the invention as electrocatalyst.
Since the g-C3N4/metal composite material according to the invention is a semiconductor whose band gap is changed by way of doping etc., it is catalytically active. This is why it can also be used as a photocatalyst, electrocatalyst or photoelectrocatalyst, next to the storage of hydrogen.
Optionally, the invention relates to a method for the photoelectrocatalysis of water and for the production of hydrogen comprising the introduction of g-C3N4/metal composite nanoflakes according to the invention into water. Optionally, the g-C3N4/metal composite nanoflakes introduced into water are irradiated with a radiation source, which optionally is a UV/Vis source. Optionally, the radiation source emits electromagnetic radiation having a wavelength between 200 nm and 1000 nm.
Further optional features of the present invention become apparent from the patent claims, the figures and the description of the embodiments.
In the following, the present invention will be explained in detail with reference to exemplary embodiments.
In the figures:
Fig. 1 shows the hydrogen storage capacity of a g-C3N4/metal composite material according to a first embodiment;
Fig. 2 shows the hydrogen storage capacity of a g-C3N4/metal composite material according to a second embodiment; and Fig. 3 shows the hydrogen storage capacity of a g-C3N4/metal composite material according to a third embodiment with voltage-assisted loading.
Embodiment 1 The first embodiment shows the production of a g-C3N4/iron composite material, whereby a mixture of 2 wt% iron(III) phosphate, 95 wt% urea and 3 wt%
polyacrylonitrile is used as the starting material. The components are mixed and ground in a ball mill for about 45 min at 600 rpm to form a starting material having an average particle size of less than 100 nm.
The resulting starting material is dispersed in as little water as possible using a disperser and an ultrasonic bath at a temperature of approximately 95 C.
When the dispersion is complete, the water is removed, and the remaining material is pyrolized in a N2 atmosphere at a pyrolysis temperature of approximately 550 C
for approximately 5 hours. Until the pyrolysis temperature is reached, the heating rate is approximately 5 C/min.
A layered bulk g-C3N4/ composite material is obtained, wherein iron(III) oxide is included between the layers.
Then the produced bulk g-C3N4/ composite material is exfoliated by ultrasound treatment to form g-C3N4/metal composite nanoflakes.
The compound can be used as a hydrogen storage material. At up to 25 bar, a hydrogen storage capacity of 9.2 wt% can be achieved at around -20 C and a hydrogen storage capacity of 6.1 wt% at around 25 C. A substantially complete desorption takes place at approximately 80 C.
Fig. 1 shows the hydrogen storage capacity of the g-C3N4/metal composite material produced according to the first embodiment as a function of pressure and in comparison between approximately -20 C (black circles) and approximately 25 C (white circles).
Embodiment 2 The second embodiment shows the production of a g-C3N4/iron-titanium composite material, wherein a mixture of 1 % wt% iron(III) phosphate, 95 wt% urea and 3 wt%
polyacrylonitrile with the further addition of 1 wt% titanium dioxide is used.

The further method steps are carried out in the same way as in the first embodiment.
Ti-doped g-C3N4/Fe composite nanoflakes are obtained, which can be used as hydrogen storage material. At up to 25 bar, a hydrogen storage capacity of 9.6 wt% can be achieved at around -20 C and a hydrogen storage capacity of 6.3 wt% at around 25 C. A substantially complete desorption takes place at approximately 80 C.
Fig. 2 shows the hydrogen storage capacity of the g-C3N4/metal composite material produced according to the second embodiment as a function of pressure and in comparison between approximately -20 C (black circles) and approximately 25 C
(white circles).
Embodiment 3 The third embodiment shows the production of a g-C3N4/iron-titanium composite material, wherein a mixture of 3 wt% iron(III) phosphate, 90 wt% urea and 5 wt%
polyacrylonitrile with the further addition of 1 wt% titanium dioxide is used as starting material. The components are mixed and ground in a ball mill for about 45 min at 600 rpm to form a starting material with an average particle size of less than 100 nnn.
The resulting starting material is dispersed in as little water as possible using a disperser and an ultrasound bath at a temperature of approximately 95 C.
When the dispersion is complete, the water is removed, and the remaining material is pyrolized in a N2 atmosphere at a pyrolysis temperature of about 450 C for about 5 hours. Until the pyrolysis temperature is reached, the heating rate is approx.
5 C/min.
A layered bulk g-C3N4/metal composite material is obtained, wherein iron(III) phosphate is included between the layers.
Then the produced bulk g-C3N4/ composite material is exfoliated by ultrasonic treatment to form g-C3N4/metal composite nanoflakes.

The compound can be used as a hydrogen storage material. At up to 25 bar, a hydrogen storage capacity of 7.4 wt% can be achieved.
If the composite material is loaded under the additional influence of an electric field with a voltage of around 1400 V, a hydrogen storage capacity of 11.7 wt% can be achieved.
Fig. 3 shows the hydrogen storage capacity of the g-C3N4/metal composite material produced according to the third embodiment as a function of pressure, comparing the capacity without voltage-assisted loading (black circles) and with voltage-assisted loading (white circles).
Embodiment 4 The g-C3N4/metal composite material with Ti and Fe produced according to the third embodiment can - like any other composite materials according to the invention - be used as an electrophotocatalyst in the production of hydrogen and oxygen from water.
If a dispersion of the g-C3N4/metal composite material in water is irradiated using a UV/Vis source, a hydrogen production rate of around 35.3 mmol/(g*h) can be achieved.
During the generation of hydrogen, an overvoltage of about 96 mV can be measured.
The electrical current density is approximately 2.67 mA/an.

Claims (15)

Claims
1. A method for producing g-C3N4/metal composite material nanoflakes, the method comprising the following steps:
a. providing a starting material comprising or consisting of an iron compound, a g-C3N4 precursor material and a polymer, i. wherein the iron compound is FePO4.
ii. wherein the g-C3N4 precursor material is urea, and iii. wherein the polymer is polyacrylonitrile, wherein the starting material is in the form of powder with particles having an average particle size of less than 100 nm, b. dispersing the starting material in a solvent, wherein the solvent is water, c. removing the solvent to form a premix containing the starting material, d. heating the premix and pyrolyzing the premix at a pyrolysis temperature between 200 C and 700 C, preferably between 400 C and 600 C to form a bulk g-C3N4/metal composite material.
e. treating the bulk-g-C3N4/metal composite material with ultrasound to form g-C3N4/metal composite material nanoflakes.
2. The method according to claim 1, characterised in that the amount of the iron compound in step (a) is between 1.0 wt% and 20 wt% with respect to the total amount of the starting material.
3. The method according to claim 1 or 2, characterised in that dispersing in step (b) is carried out at a temperature between 80 C and 100 C, preferably between 90 C
and 100 C, and optionally with ultrasound treatment.
4. The method according to any one of claims 1 to 3, characterised in that the heating rate during heating to the pyrolysis temperature in step (d) is greater than or equal to 5 C/min.
5. The method according to any one of claims 1 to 4, characterised in that the pyrolysis temperature in step (d) is approximately 450 C, or in that the pyrolysis temperature in step (d) is approximately 550 C.
6. The method according to one of claims 1 to 5, characterised in that the method comprises the following further step after step (d):
- reducing the iron in the g-C3N4/metal composite material.
7. The method according to any one of claims 1 to 6, characterised in that in step (a) a further metal compound is added, wherein the further metal compound is selected from an aluminium, lithium, magnesium, titanium, nickel, platinum, palladium, vanadium compound or any mixture of these compounds.
8. The method according to claim 7, characterised in that the amount of the further metal compound in step (a) is between 0.5 wt% and 5.0 wt%, preferably approximately 1.0 wt%, with respect to the total amount of the starting material.
9. The method according to any one of claims 1 to 8, characterised in that the pyrolysis in step (d) takes place in an inert gas atmosphere, in particular in a nitrogen atmosphere.
10. A g-C3N4/metal composite material in the form of nanoflakes obtainable by a method according to any one of claims 1 to 9, wherein g-C3N4/nanoflakes are provided on the surface of which iron and/or the iron compound is carried, wherein the iron and/or the iron compound is in the particulate form with a particle diameter of less than 100 nm.
11. The composite material according to claim 10, comprising pores having an average pore size of less than 100 nm.
12. A hydrogen storage material comprising or consisting of g-C3N4/metal composite material according to any one of claims 10 or 11.
13. An electrocatalyst for water electrolysis comprising or consisting of g-C3N4/metal composite material according to any one of claims 10 or 11.
14. A photocatalyst for water electrolysis comprising or consisting of g-C3N4/metal composite material according to any one of claims 10 or 11.
15. A photoelectrocatalyst for water electrolysis comprising or consisting of g-C3N4/metal composite material according to any one of claims 10 or 11.
CA3240144A 2021-12-10 2022-12-02 Process for producing nanoflakes from g-c3n4/metal composite material Pending CA3240144A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
ATA50989/2021 2021-12-10
ATA50989/2021A AT525570B1 (en) 2021-12-10 2021-12-10 Process for preparing g-C3N4/metal composite nanoplates
PCT/AT2022/060424 WO2023102584A1 (en) 2021-12-10 2022-12-02 Process for producing nanoflakes from g-c3n4/metal composite material

Publications (1)

Publication Number Publication Date
CA3240144A1 true CA3240144A1 (en) 2023-06-15

Family

ID=84463020

Family Applications (1)

Application Number Title Priority Date Filing Date
CA3240144A Pending CA3240144A1 (en) 2021-12-10 2022-12-02 Process for producing nanoflakes from g-c3n4/metal composite material

Country Status (9)

Country Link
US (1) US20250041837A1 (en)
EP (1) EP4436912B1 (en)
JP (1) JP2024546766A (en)
KR (1) KR20240121269A (en)
CN (1) CN118401463A (en)
AT (1) AT525570B1 (en)
AU (1) AU2022406425A1 (en)
CA (1) CA3240144A1 (en)
WO (1) WO2023102584A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117887251B (en) * 2024-01-09 2024-09-13 中山市科倍隆工程塑料有限公司 Wear-resistant flame-retardant engineering plastic alloy and preparation method thereof
CN119219135B (en) * 2024-12-02 2025-06-10 山东太平洋环保股份有限公司 Particle electrode for strengthening electrocatalytic degradation of pollutants in industrial wastewater, and preparation method and application thereof
US12534364B1 (en) 2025-02-25 2026-01-27 Imam Mohammad Ibn Saud Islamic University Nanocomposite for hydrogen generation

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104437643A (en) * 2014-11-04 2015-03-25 内蒙古民族大学 Solid super-molecular photocatalyst integrating Fenton effect and photocatalysis as well as preparation method and application thereof
CN108246333A (en) * 2018-01-18 2018-07-06 浙江大学 A kind of transition metal nano-composite catalyst and its preparation method and application
CN110429277B (en) * 2019-06-28 2021-01-29 合肥国轩高科动力能源有限公司 Preparation method of high-compaction high-rate lithium iron phosphate cathode material
CN110479345A (en) * 2019-09-02 2019-11-22 中建材蚌埠玻璃工业设计研究院有限公司 A kind of g-C3N4The preparation method of the iron oxide photocatalyst of quantum dot modification
CN112156662B (en) * 2020-09-30 2021-09-07 东华大学 A kind of self-cleaning electrospinning nanofiber filter membrane, preparation method and application
CN112938936B (en) * 2021-03-17 2023-08-15 西安交通大学 Metal atom loaded nanocomposite and preparation method thereof

Also Published As

Publication number Publication date
CN118401463A (en) 2024-07-26
US20250041837A1 (en) 2025-02-06
EP4436912B1 (en) 2026-02-04
KR20240121269A (en) 2024-08-08
EP4436912C0 (en) 2026-02-04
AU2022406425A1 (en) 2024-07-04
WO2023102584A1 (en) 2023-06-15
JP2024546766A (en) 2024-12-26
AT525570A4 (en) 2023-05-15
EP4436912A1 (en) 2024-10-02
AT525570B1 (en) 2023-05-15

Similar Documents

Publication Publication Date Title
US20250041837A1 (en) Process for producing nanoflakes from g-c3n4/metal composite material
Zhu et al. A Facile Strategy for Constructing a Carbon‐Particle‐Modified Metal–Organic Framework for Enhancing the Efficiency of CO2 Electroreduction into Formate
Wang et al. Fabricating carbon quantum dots of graphitic carbon nitride vis ultrasonic exfoliation for highly efficient H2O2 production
Liu et al. Controllable synthesis of cobalt monoxide nanoparticles and the size-dependent activity for oxygen reduction reaction
Zhang et al. Chitosan cross-linked poly (aminoanthraquinone)/Prussian blue ternary nitrogen precursor-derived Fe–N–C oxygen reduction catalysts for microbial fuel cells and zinc–air batteries
Zhao et al. Enhanced activity of Pt nano-crystals supported on a novel TiO 2@ N-doped C nano-composite for methanol oxidation reaction
Chen et al. Modification of multi-walled carbon nanotubes by microwave digestion method as electrocatalyst supports for direct methanol fuel cell applications
JP2024546766A5 (en)
Wang et al. Mo2C/reduced‐graphene‐oxide nanocomposite: an efficient electrocatalyst for the hydrogen evolution reaction
Ansari et al. Gas bubbling exfoliation strategy towards 3D g-C3N4 hierarchical architecture for superior photocatalytic H2 evolution
JP6684049B2 (en) Nitrogen-containing carbon material, method for producing the same, and fuel cell electrode
Zhang et al. Platinum/nitrogen-doped carbon nanoparticles synthesized in nitrogen-doped carbon quantum dots aqueous solution for methanol electro-oxidation
Ingavale et al. In situ growth of copper oxide on MXene by combustion method for electrochemical ammonia production from nitrate
Bai et al. Triphenylphosphine‐Assisted Exsolution Engineering on Ruddlesden–Popper Perovskites for Promoting Oxygen Evolution
Chen et al. Nanoconfined Solvothermal Synthesis of Defective 1T‐MoS2 Monolayers with High Electrocatalytic Performance
Zhou et al. Recent advances in high-entropy intermetallic nanoparticles: synthesis and electrocatalytic applications
Hsu et al. Nitrogen-doped mesoporous carbon hollow spheres as a novel carbon support for oxygen reduction reaction
Luo et al. A universal and ultrafast method for fabricating a library of nanocellulose-supported metal nanoparticles
Wu et al. Carbonization of ionic liquid polymer-functionalized carbon nanotubes for high dispersion of PtRu nanoparticles and their electrocatalytic oxidation of methanol
JP6716219B2 (en) Method for producing Ti4O7
Pereira et al. Printing specific active sites for ORR and hydrazine oxidation on N-doped carbon
Wang et al. Nano titania modified nanodiamonds as stable electrocatalyst supports for direct methanol fuel cells
BR112024011316B1 (en) METHODS FOR PRODUCING NANOFLOCS FROM γ-C3N4/METAL COMPOSITE MATERIAL, γ-C3N4/METAL COMPOSITE MATERIAL, HYDROGEN STORAGE MATERIAL, ELECTROCATALYST, PHOTOCATALYST AND PHOTOELECTROCATALYST
Shete et al. Synthesis of a high dielectric constant graphene supported iron oxide and its electrocatalytic activity in a H 2 O 2 fuel cell and as an efficient photocatalyst
Shibin et al. Functionalized carbon nanotubes as Pt catalyst supports in methanol oxidation

Legal Events

Date Code Title Description
MFA Maintenance fee for application paid

Free format text: FEE DESCRIPTION TEXT: MF (APPLICATION, 2ND ANNIV.) - STANDARD

Year of fee payment: 2

U00 Fee paid

Free format text: ST27 STATUS EVENT CODE: A-1-1-U10-U00-U101 (AS PROVIDED BY THE NATIONAL OFFICE); EVENT TEXT: MAINTENANCE REQUEST RECEIVED

Effective date: 20241008

U11 Full renewal or maintenance fee paid

Free format text: ST27 STATUS EVENT CODE: A-1-1-U10-U11-U102 (AS PROVIDED BY THE NATIONAL OFFICE); EVENT TEXT: MAINTENANCE FEE PAYMENT PAID IN FULL

Effective date: 20241008

MFA Maintenance fee for application paid

Free format text: FEE DESCRIPTION TEXT: MF (APPLICATION, 3RD ANNIV.) - STANDARD

Year of fee payment: 3

U00 Fee paid

Free format text: ST27 STATUS EVENT CODE: A-1-1-U10-U00-U101 (AS PROVIDED BY THE NATIONAL OFFICE); EVENT TEXT: MAINTENANCE REQUEST RECEIVED

Effective date: 20251110

U11 Full renewal or maintenance fee paid

Free format text: ST27 STATUS EVENT CODE: A-1-1-U10-U11-U102 (AS PROVIDED BY THE NATIONAL OFFICE); EVENT TEXT: MAINTENANCE FEE PAYMENT PAID IN FULL

Effective date: 20251110