Classifications

• • 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
  • B01J23/007—Mixed salts
• • 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
  • B01J23/72—Copper

Definitions

• the current disclosure describes heterogeneous materials having a p-type semiconductor comprising mixed valence oxide compounds and an n-type semiconductor having a deeper valence band than that of the p-type semiconductor, the n-type semiconductor in ionic charge communication with the mixed valence oxide compounds of the p-type semiconductor.
• These multivalent heterogeneous materials can be used to enhance the photocatalytic activity of photocatalytic materials.
• Visible light activated photocatalysts can be deployed for self-cleaning, air and water purification and many other interesting applications usually without any post- deployment non-renewable energy costs. This is because the photocatalysts are able to decompose pollutants (like dyes, volatile organic compounds and NO x ) using ambient light like solar radiation or indoor and outdoor lighting. With the anticipated rapid adoption of UV- free indoor lighting (like LEDs and OLEDs), it is imperative to find ways to deploy visible-light activated photocatalysts in indoor applications, for instance, in cleaning room air in domestic, public and commercial spaces especially in confined areas like aircraft, public buildings, etc. Moreover, additional applications for antibacterial surfaces and self-cleaning materials can have wide applicability in the food service, transportation, health care and hospitality sectors.
• Elemental copper, copper composites, alone or in combination with metal oxides, have been described as useful photocatalytic/antibacterial/antiviral materials. See United States Patent Publication Nos. 2007/0154561 , 2009/0269269, 201 1/0082026, and 2012/0201714; and, Qiu, Xiaoqing et al., "Hybrid Cu x O/Ti0 2 Nanocomposites as risk- reduction materials in indoor environments," ACS Nano, 6(2): 1609-1618 (2012). Elemental copper however, shows a degradation of antibacterial activity over time (durability) and unappealing cosmetic appearance change (from Cu metal to black CuO) both believed due to oxidation of elemental copper under normal application conditions. Thus, there is a need for improved longevity of anti-bacterial activity over time. Thus there is a need for photocatalytic materials that provide antibacterial/antiviral activity without unappealing cosmetic appearance changes. SUMMARY OF THE DISCLOSURE
• the current disclosure describes heterogeneous materials having a p-type semiconductor comprising mixed valence oxide compounds and an n-type semiconductor having a deeper valence band than that of the p-type semiconductor wherein the semiconductors are in ionic charge communication with each other.
• These multivalent heterogeneous materials can be used to enhance the photocatalytic activity of photocatalytic materials and to improve durability (i.e. maintain photocatalytic activity over time).
• Photocatalytic materials are useful for having and/or enhancing anti-bacterial (light and dark) activity, anti-viral activity, decomposition of volatile organic compounds (VOC) and/or dye discoloration in aqueous solutions.
• Some embodiments include a heterogeneous material comprising: a p-type semiconductor comprising a first metal oxide compound and a second metal oxide compound, wherein the first metal oxide compound and the second metal oxide compound have different oxidation states of the same metal, and wherein the p-type semiconductor has a p-type valence band; and an n-type semiconductor having an n-type valence band which is deeper than the p-type valence band, wherein the n-type semiconductor is in ionic charge communication with the p-type semiconductor.
• Another embodiment further comprises a noble metal in ionic charge communication with the mixed valence oxide compounds.
• the noble metal is rhodium, ruthenium, palladium, silver, osmium, platinum or gold.
• the noble metal is loaded onto the n-type semiconductor.
• Another embodiment further comprises a second n-type semiconductor, wherein at least a portion of the second n-type semiconductor is ionic charge isolated from the mixed valence oxide compounds
• the second n-type semiconductor comprises a cerium oxide.
• the cerium oxide is Ce0 2 .
• the second n-type semiconductor comprises plural phase T1O2.
• the mixed valence oxide compounds comprise a pair of the same metallic chemical element, e.g. Cu, Co, Mn, Fe, Ir, etc., in two different oxidation states, such as the pairs copper(l) and copper(ll); cobalt (II) and cobalt (III); Mn(ll) and Mn(lll); Fe(ll) and Fe(lll); or, Ir(lll) and Ir(IV).
• the p-type semiconductor is loaded onto the n-type semiconductor.
• the p-type semiconductors are substantially uniformly dispersed onto the n-type semiconductor.
• the mixed valence oxide compounds have a particle size of 100 nm or less.
• the copper(l) and copper (II) compound is a Cu x O compound.
• the Cu x O compound is chemically valence controlled.
• the ratio of copper(l):copper (II) is between 10:90 to 90:10.
• the p-type semiconductor is 0.001 to 10 wt% of the heterogeneous material and the p-type semiconductor is 90 to 99.999 wt% of the heterogeneous material.
• the n-type semiconductor can be any suitable semiconductor wherein the charge carriers are electrons, such as electrons in the conduction band which are donated from a donor band of a dopant.
• the n-type semiconductor is an oxide comprising cerium, tungsten, tantalum, tin, zinc, strontium, zirconium, barium, indium or aluminum oxide.
• the n-type semiconductor is Sn-Ti(0,C,N) 2 , Ce0 2 , KTa0 3 , Ta 2 0 5 , Sn0 2 , W0 3 , ZnO, SrTi0 3 , BaTi0 3 , ZrTi0 4 , ln 2 Ti0 5 , AI 2 Ti0 5 , or LiCa 2 Zn 2 V 3 0i 2 .
• the n-type semiconductor is Sn-Ti(0,C,N) 2
• the n-type semiconductor is AI 2 . x ln x Ti0 5 wherein 0 ⁇ x ⁇ 2.
• the n-type semiconductor is Zr 1 . y Ce y Ti0 4 wherein 0 ⁇ y ⁇ 1.
• the n-type semiconductor can comprise an oxide comprising titanium.
• the oxide comprising titanium comprises a plural phase titanium oxide.
• the plural phase titanium oxide comprises a mixture of anatase Ti0 2 phase and rutile Ti0 2 phase.
• the n-type semiconductor is a titanium oxide having a dopant.
• a dopant could donate electrons to the conducting band of titanium oxide.
• the n-type semiconductor is a titanium oxide doped with N, C, or both.
• the n-type semiconductor is a titanium oxide comprising a compound represented by the formula (Ti ⁇ r M r )(0 2 - s - t C s N t ), wherein: M is Sn, Ni, Sr, Ba, Fe, Bi, V, Mo, W, Zn, or Cu, or combinations thereof; r is in the range of 0 to 0.25; s is in the range of 0.001 to 0.1 ; and, t is in the range of 0.001 to 0.1.
• Another embodiment comprises a photocatalyst (Tio .99 Sn 0 .oi)(0 2 . s .tC s Nt), (Tio .97 Sn 0 3 )(0 2 _s_tC s N t ), (Tio.9 5 Sno.o5)(0 2 _ s _tC s N t ), (Tio.9oSn 0 .io)(0 2 _ s _tC s N t ), (Tio.85Sno.i 5 )(0 2 _ s _tC s N t ),
• Some embodiments include a method of decomposing a chemical compound, comprising exposing the chemical compound to a photocatalyst comprising a homogeneous material described herein in the presence of light.
• the chemical compound is a pollutant, such as a volatile organic compound.
• Some embodiments include a method of killing a microbe, comprising exposing the microbe to a photocatalyst comprising a homogeneous material described herein in the presence of light.
• a particular embodiment as described herein includes a method for loading a mixed valence compound.
• This method can include adding a dispersing agent to a mixed valence- type compound to more positively charge the surface of the n-type compound; adding an attracting agent to the n-type compounds to make the surface charge of the n-type semiconductor more negative; and, mixing the dissimilarly charged materials with each other at a temperature below the doping temperature of the mixed valence compound.
• FIG. 1A is a schematic showing the relationship between conduction energy bands with valence energy bands for metal materials.
• FIG. 1 B is a schematic showing the relationship between conduction energy bands with valence energy bands for semi-conductor materials.
• FIG. 1 C is a schematic showing the relationship between conduction energy bands with valence energy bands for non-conducting materials.
• FIG. 2 is a schematic showing the conduction and valence energy band levels for various compounds described herein.
• FIG. 3 shows the x-ray diffraction patterns of an embodiment of a p-type and n-type composite material described herein with that of the n-type material alone.
• FIG. 4 shows the x-ray diffraction patterns of another embodiment of a p-type and n-type composite material described herein with that of the n-type material alone.
• FIG. 5 shows the x-ray diffraction patterns of another embodiment of a p-type and n-type composite material described herein with that of the n-type material alone.
• FIG. 6 shows the diffuse reflectance spectra comparing embodiments of a p-type and n-type composite material described herein and that of the n-type material alone
• FIG. 7 shows the diffuse reflectance spectra comparing another embodiment of a p- type and n-type composite material described herein that of the n-type material alone (Ce0 2 ).
• FIG. 8 shows the diffuse reflectance spectra comparing another embodiment of a p- type and n-type composite material described herein that of the n-type material alone.
• FIG. 9 is a graph showing the decomposition of acetylaldehyde by various photocatalytic composites, Ex-1A and CE-1 described herein.
• FIG. 10 is a graph showing the antibacterial activity (CFU/Specimen) on E.Coli by various photocatalystic composites, Ex-1A and CE-1 described herein after exposure to visible light of 800 lux from a fluorescent lamp.
• FIG. 1 1 is a graph showing the antibacterial activity (CFU/Specimen) on E.Coli by various photocatalytic composites, Ex-4 and CE-2 described herein after exposure to visible light of 800 lux from a fluorescent lamp.
• Fig.12A is a graph showing the enhanced durability antibacterial activity on E. coli by photocatalytic composites, Ex-1 , before and after being treated at 85° C and 85% relative humidity (RH) for 7 days.
• Fig. 12B is a graph showing the enhanced durability antibacterial activity on E. coli by photocatalytic composites, Ex-7, before and after treated at 300° C for 20 min.
• Fig. 13 is a graph showing the dye discoloration of natural blue color by various photocatalytic composites, Example 1 and CE-1 described herein along with rutile Ti0 2 with and without Cu x O loading.
• Fig.14 is a graph showing the decomposition of acetaldehyde by various photocatalytic composites, Ex-12, 13, 15, 16 and CE-6 described herein.
• Fig. 15 is a graph showing the dye discoloration of blue dye color by various photocatalytic composites, Example 19 and Sn0 2 without loading.
• Fig. 16 is a graph showing the dye discoloration of natural blue color by various photocatalytic composites, Ex-18.
• Fig. 17 is a graph showing the effect of a physical mixture of CE-0 (0.25 wt.% CuO + 0.12 wt.% Cu 2 0 + 0.5 wt.% Sn doped Ti(OCN) 2 photocatalyst) on E. coli killing property.
• Fig. 18 is a graph showing the effect of Ex-7A (0.5 wt.% Cu x O loaded alumina (non- photocatalyst)) on antibacterial property ⁇ E. coli killing study).
• Fig. 19 is a graph showing the effect of Ex- 1 B (0.5 wt.% Cu x O loaded Sn doped Ti(OCN)2 photocatalyst) on antibacterial property (E. coli killing study).
• Fig. 20 is a graph showing the synergy effect of Ex-1 (1 wt.% Cu x O loaded Sn doped Ti(OCN) 2 ) on antibacterial property (E. coli killing study) .
• Fig. 21 is a graph showing the enhanced durability result of Ex-1 (1wt.% Cu x O loaded Sn doped Ti(OCN) 2 ) on antibacterial property (E. coli killing study).
• Fig. 22 is a graph showing the synergy effect of Cu x O/P25 and Cu x O/AI 2 0 3 on antibacterial property (E. coli killing study) .
• Fig. 23 is a graph showing the enhanced durability result of Cu x O/P25 and Cu x O/AI 2 0 3 on antibacterial property (E. coli killing study). DETAILED DESCRIPTION
• the current disclosure describes heterogeneous materials having a p-type semiconductor comprising a mixed valence oxide compound.
• the p-type semiconductor has a p-type valence band.
• the heterogeneous material also comprises an n-type semiconductor having an n-type valence band which is deeper valence band than the p-type valence band.
• the n-type semiconductor is in ionic charge communication with the mixed valence oxide compound.
• These multivalent heterogeneous materials can be used to enhance the photocatalytic activity of photocatalytic materials and to improve durability (i.e. maintain photocatalytic activity over time).
• Photocatalytic materials are useful for having and/or enhancing anti-bacterial (light and dark) activity, anti-viral activity, decomposition of volatile organic compounds (VOC) and/or dye discoloration in aqueous solutions.
• a conduction band 10 is a range of electron energies enough to free an electron from binding with its atom to move freely within the atomic lattice of the material as a 'delocalized electron'.
• the valence band 20 is the highest range of electron energies in which electrons are normally present at absolute zero temperature. The valence electrons are substantially bound to individual atoms, as opposed to conduction electrons (found in semiconductors), which can move more freely within the atomic lattice of the material.
• the valence band 20 is generally located below the conduction band, separated from it in insulators and semiconductors by a band gap 30.
• the conduction band has substantially no discernible energy gap separating it from the valence band.
• the conduction and valence bands may actually overlap (overlap 25), for example, when the valence band level energy is higher or less negative than the conduction band level energy.
• Various materials may be classified by their band gap; e.g., classified by the difference between the valence band 20 and conduction band 10.
• non-conductors e.g., insulators
• the conduction band is much higher energy than the valence band, so it takes much too much energy to displace the valence electrons for an insulator to effectively conduct electricity.
• These insulators are said to have a non-zero band gap.
• conductors, such as metals that have many free electrons under normal circumstances, the conduction band 10 overlaps 25 with the valence band 20 - there is no band gap, so it takes very little or no additional applied energy, to displace the valence electrons.
• the band gap is small, on the order of 200 nm to 1000 nm. While intending to be bound by theory, this is believed to be the reason that it takes relatively little energy (in the form of heat or light) to make semiconductors' electrons move from the valence band to another energy level and conduct electricity; hence, the name semiconductor.
• an heterogeneous material comprises a p- type semiconductor comprising a mixed valence oxide compound, the compound having a p- type conduction band and a p-type valence band; and, a separate n-type semiconductor having an n-type valence band that is deeper, lower energy, or more negative than the p- type valence band.
• the n-type semiconductor should be in ionic charge communication with the p-type semiconductor, meaning that ionic charge can be transferred from the n-type semiconductor to the mixed valence oxide compound, or from the mixed valence oxide compound to the n-type semiconductor. Examples of suitable conduction bands and valence bands are shown in FIG. 2.
• the materials in ionic communication are loaded onto one another. By loading, the materials retain their separate identity; e.g., Cu x O (p-type semiconductor) separate from ⁇ 2, , Ti(OCN) 2 :Sn, etc. (n-type semiconductor).
• one material is on the surface, in contact with or in close proximity to the other, as opposed to doping, physically separated from the other, ionic charge isolated or admixing (physical mixing).
• contact and/or isolation can be determined by transmission electron microscopy (TEM) examination of the p-type and n-type materials.
• the heterogeneous materials are integrated within a compound matrix; e.g., incorporated into the compound/crystal lattice.
• a heterogeneous material may comprise any suitable p-type semiconductor, including any semiconductor wherein the charge carrier is effectively positive holes. These holes may be present in a p-type valence band, which can be essentially full of electrons, except for a few holes which may essentially carry the positive charge.
• a p-type semiconductor may comprise a mixed valence oxide compound having a p-type valence band.
• the mixed valence oxide compounds comprise a mixed valence pair of the same metallic element, such as copper(l) and copper(ll); cobalt (II) and cobalt (III); Mn(ll) and Mn(lll); Fe(ll) and Fe(lll); and/or, Ir(lll) and Ir(IV); and, combinations thereof.
• copper (I) and copper (II) compounds can be Cu x O compounds.
• the mixed valence oxide compounds can include Cu 1+ and Cu 2+ . Ratios of mixed valence oxide compounds can be 10% to 90% to 90% to 10%.
• Particular ratios can also include: 15% to 85%; 20% to 80%; 25% to 75%; 30% to 70%; 35% to 65%; 40% to 60%; 45% to 55%; 50% to 50%; 55% to 45%; 60% to 40%; 65% to 35%; 70% to 30%; 75% to 25%; 80% to 20%; and 85% to 15%.
• the mixed valence metal oxide compounds are Cu 1 + :Cu 2+ at a ratio of 10% to 90% Cu 1 + to 90% to 10% Cu 2+ .
• the ratio of Cu 1 + :Cu 2+ can also be about 10%:90% to about 30%:70%, about 15%:85% to about 25%:75%, about 15%:85%; about 20%:80%; about 25%:75%; about 30%:70%; about 35%:65%; about 40%:60%; about 45%:55%; about 50%:50%; about 55%:45%; about 60%:40%; about 65%:35%; about 70%:30%; about 75%:25%; about 80%:20%; or about 85%: 15%.
• the ratios are Cu 1 + :Cu 2+ wt%.
• the ratios are Cu 1 + :Cu 2+ molar%.
• the p-type semiconductor is loaded onto the n-type semiconductor.
• the p-type semiconductor can be embedded, layered, in contact with and/or deposited onto the n-type semiconductor.
• the p-type semiconductor mixed valence compounds are substantially uniformly dispersed onto the n-type semiconductor.
• the particle size of the mixed valence compounds can be less than 200 nm; less than 190 nm; less than 180 nm; less than 170 nm; less than 160 nm; less than 150 nm; less than 140 nm; less than 130 nm; less than 120 nm; less than 1 10 nm; less than 100 nm; less than 90 nm; less than 80 nm; less than 70 nm; less than 60 nm; less than 50 nm; less than 40 nm; less than 30 nm; less than 20 nm; or, less than 10 nm.
• the particle size of the mixed valence compounds is 100 nm or less.
• the p-type semiconductor comprises from 0.001 to 10 wt% of the heterogeneous material and the n-type semiconductor comprises from 99.999 to 90 wt% of the heterogeneous material.
• the p-type semiconductor comprises 0.001 wt% of the heterogeneous material; 0.005 wt% of the heterogeneous material; 0.01 wt% of the heterogeneous material; 0.05 wt% of the heterogeneous material; 0.1 wt% of the heterogeneous material; 0.5 wt% of the heterogeneous material; 1 wt% of the heterogeneous material; 2 wt% of the heterogeneous material; 3 wt% of the heterogeneous material; 4 wt% of the heterogeneous material; 5 wt% of the heterogeneous material; 6 wt% of the heterogeneous material; 7 wt% of the heterogeneous material; 8 wt% of the
• the n-type semiconductor comprises 90 wt% of the heterogeneous material; 91 wt% of the heterogeneous material; 92 wt% of the heterogeneous material; 93 wt% of the heterogeneous material; 94 wt% of the heterogeneous material; 95 wt% of the heterogeneous material; 96 wt% of the heterogeneous material; 97 wt% of the heterogeneous material; 98 wt% of the heterogeneous material; 99 wt% of the heterogeneous material; 99.1 wt% of the heterogeneous material; 99.2 wt% of the heterogeneous material; 99.3 wt% of the heterogeneous material; 99.4 wt% of the heterogeneous material; 99.5 wt% of the heterogeneous material; 99.6 wt% of the heterogeneous material; 99.7 wt% of the heterogeneous material; 99.
• the p-type semiconductor comprises a mixture of copper oxides, such as a first copper oxide compound and a second copper oxide, such as a Cu (I) compound (e.g. Cu 2 0) and a Cu (II) compound (e.g. CuO).
• the p- type semiconductor comprises Cu (I) (e.g. Cu 2 0) and Cu (II) (e.g. CuO) in a weight:weight or a mole:mole ratio [Cu (l):Cu (II)] of about 1 :9 to about 3:7, about 1 :3 to about 1 :6, or about 1 :3 to about 1 :4.
• Some embodiments include a p-type semiconductor of the previous paragraph in combination with a n-type semiconductor that is a titanium oxide or Ti(0,C,N) 2 doped with tin, or a titanium oxide, such as Ti0 2 , having more than one phase.
• a Ti0 2 can have two phases, such as rutile Ti0 2 and anatase Ti0 2 .
• the n-type semiconductor can be about 70% to about 90% anatase phase and 10% to about 30% rutile phase Ti0 2 , about 80% to about 90% anatase phase and 20% to about 30% rutile phase Ti0 2 , about 75% to about 80% anatase phase and 15% to about 20% rutile phase Ti0 2 , or about 83% anatase phase Ti0 2 and 17% rutile phase Ti0 2 .
• Some embodiments include a p-type semiconductor of the previous paragraph in combination with a n-type semiconductor that is tin oxide.
• the copper oxides may be about 0.1 % to about 5%, about 0.2% to about 2%, about 0.2% to about 1.5%, about 0.5%, or about 1 % of the total weight of the n- and p-type semiconductors.
• the p-type semiconductor is loaded onto the n-type semiconductor.
• the n-type semiconductor is an oxide comprising an element that can be cerium, tungsten, tantalum, tin, zinc, strontium, zirconium, barium, indium, or aluminum oxide having a valence band deeper than that of the p-type semiconductor pair valence bands.
• the n-type semiconductor can be anatase, rutile, wurtzite, spinel, perovskite, pyrochlore, garnet, zircon and/or tialite phase material or mixtures thereof. Each of these options is given its ordinary meaning as understood by one having ordinary skill in the semiconductor art.
• Comparison of an x-ray diffraction pattern of a given standard and the produced sample is one of a number of methods that may be used to determine whether the sample comprises a particular phase.
• Exemplary standards include those XRD spectra provided by the National Institute of Standards and Technology (NIST) (Gaitherburg, Maryland, USA) and/or the International Centre for Diffraction Data (ICDD, formerly the Joint Committee on Powder Diffraction Standards [JCPDS]) (Newtown Square, Pennsylvania, USA).
• the perovskite can be a perovskite oxide.
• the n-type semiconductor can comprise cerium, tungsten, tantalum, tin, zinc, strontium, zirconium, barium, indium, niobium, vanadium, iron, cadmium, germanium and/or aluminum oxide.
• the n-type semiconductor can also comprise Ce0 2 ; MgTa 2 0 6 ; BaTa 2 0 6 ; SrTa 2 0 6 ; Ta 2 0 5; FeTa 2 0 6 ; Hg 2 Ta 2 0 7 ; Hg 2 Nb 2 0 7 ; Hg 2 Ta v Nbi -v 0 7 ; K 3 Ta 3 Si 2 0 13 ; K 2 LnTa 5 0 15 ; W0 3 ; ZnO; SrTi0 3 ; SrNb 2 0 7 ; SrTa 2 0 7 ; SrTaNb0 7 ; Sr 2 FeNb0 6 ; Sr 3 FeNb 2 0 9 ; Ti0 2 ; Sn0 2 ; BaTi0 3 ; FeTi0 3 ; CdFe 2 0 4 ; MnTi0 3 ; Cs 2 Nb 4 0n ; KNb0 3 ; Sr 2 FeN
• the n-type semiconductor can be a vanadium garnet semiconducting photocatalyst.
• the vanadium garnet semiconducting photocatalyst can be represented by the formula: (Ai -x O x )3(M)2(V 3 )Oi2, wherein 0 ⁇ x ⁇ 1 .
• the cumulative ionic charge of (Ai_ x O x ) 3 and (M) 2 is +9.
• a + can be Li + , Cu + , Na + , K + , Ti + , Cd 2+ , Ca 2+ , Sr 2 *, Pb 2+ , Y 3+ , Bi 3+ , Ln 3+ , or combinations thereof.
• M can be one or any of Li + , Ni 2+ , Mg 2+ , Co 2+ , Cu 2+ , Zn 2+ , Mn 2+ , Cd 2+ , Cr 3+ , Fe 3+ , or Sc 3+ or combinations thereof.
• the n-type semiconductor can be a vanadium garnet semiconducting photocatalyst.
• the vanadium garnet semiconducting photocatalyst can be represented by Formula 1 : (A 2+ ) 3 (M + M 2+ )(V 3 )Oi 2 .
• the vanadium garnet semiconducting photocatalyst can be Ca 3 LiZnV 3 0i 2 and/or Sr 3 LiZnV 3 0i 2 .
• the n-type semiconductor can be a mixed titanate.
• the term "mixed titanate” refers to a compound that comprises Ti, O and at least another element; e.g., Ca, Cu, Mg, or La.
• the mixed titanate can be CaCu 2 Ti 3 0i 2 (perovskite titanate); MgTi 2 0 5 (pseudobrookite); and/or, La 2 Ti 2 0 7 (pyrochlore titanate).
• the Ti oxide can comprise a mixture of anatase and rutile Ti0 2 .
• the n-type semiconductor can comprise a mixed copper oxide.
• Mixed copper oxide refers to an n-type semiconductor comprising Cu, O and another element different from copper and oxygen.
• the mixed Cu oxide can be CuMn0 2 or CuFe0 2 .
• the n-type semiconductor can be a simple or mixed ferrite.
• the mixed ferrite can be Alpha-Fe 2 0 3; MFe 2 04, where M is Mg, Zn, Ca, Ba or combination of them; Ca 2 Fe 2 0 5, MFei 2 0i 9 , where M is Sr, Ba or combination of them; Sr 7 Fei 0 O 22, MFe0 2.5+x , where M is Sr, Ba or combination of them, Sr 3 Fe 2 0 6 .i6 ; Bii.5Pbo. 5 Sr 2 BiFe 2 C>9. 2 5; Pb 2 Sr 2 BiFe 2 0 9+y; Bi 2 Sr 2 BiFe 2 0 9+y; and/or, Bi 1 . 5 Pbo.5Sr 4 Fe20 1 o.o4.
• the n-type semiconductor can be a Cu x O loaded oxynitride semiconducting photocatalyst.
• the oxynitride semiconducting photocatalyst can comprise TaON; MTa0 2 N, wherein M is Ca, Sr, Ba or combination of them; SrNb 2 0 7 - x N x ; (Gai -x Zn x )(Ni -x O x ); and/or (Zn 1+x Ge)(N 2 O x ).
• the n-type semiconductor can be a Cu x O loaded sulfide, selenide or sulfoselenide semiconducting photocatalyst.
• the sulfide, selenide or sulfoselenide semiconducting photocatalyst can comprise Cd(S y ,Sei- y ), wherein 0 ⁇ y ⁇ 1 ; (Cd,Zn(S y ,Sei- y ), wherein 0 ⁇ y ⁇ 1 ; (Agln) x Zn 2(1 . x) (S y ,Sei.
• the n-type semiconductor comprises a compound represented by the formula AI 2 . x ln x Ti0 5 , wherein x is in the range of 0 to 2 (0 ⁇ x ⁇ 2).
• the n-type semiconductor comprises a compound represented by the formula Zr 1 . y Ce y Ti0 4 , wherein y is in the range of 0 to 1 (0 ⁇ y ⁇ 1 ).
• the n-type semiconductor is a titanium oxide having a valence band controlled through doping.
• the n-type semiconductor is a titanium oxide doped with N or C or both.
• the titanium oxide comprises a compound represented by the formula (Tii_ r M r )(0 2 - s - t C s N t ), wherein M is Sn, Ni, Sr, Ba, Fe, Bi, V, Mo, W, Zn, Cu or combinations thereof; r is in the range of 0 to 0.25; s is in the range of 0.001 to 0.1 ; and, t is in the range of 0.001 to 0.1. In some embodiments, r is no more than 0.20.
• r can more particularly be 0; 0.01 ; 0.02; 0.03; 0.04; 0.05; 0.06; 0.07; 0.08; 0.09; 0.10; 0.1 1 ; 0.12; 0.13; 0.14; 0.15; 0.16; 0.17; 0.18; 0.19; 0.20; 0.21 ; 0.22; 0.23; 0.24; or 0.25.
• s can more particularly be 0.001 ; 0.005; 0.01 ; 0.02; 0.03; 0.04; 0.05; 0.06; 0.07; 0.08; 0.09; or 0.1 .
• t can more particularly be 0.001 ; 0.005; 0.01 ; 0.02; 0.03; 0.04; 0.05; 0.06; 0.07; 0.08; 0.09; or, 0.1 .
• M is Sn, Ni, Sr, Ba, Fe, Bi, or combinations thereof.
• r is in the range of 0.0001 to 0.15. In some embodiments, M is Sn. In some embodiments, r is at least 0.001 .
• the n-type semiconductor comprises (Ti 0 .99Sno.oi )(0 2 - s - t CsNt), (Tio.97Sno.o3)(0 2 -s-tC s Nt), (Tio.9 5 Sno.o5)(0 2 _ s _tC s Nt), (Tio.9oSno.io)(0 2 -s-tC s Nt), (Tio.8 5 Sno.i5)(0 2 _ s _ tC s N t ), (Tio.985Nio.oi5)(0 2 -s-tC s Nt), (Tio.9 8 Nio.o 2 )(0 2 _ s _tC s Nt), (Tio.9 7 Nio.o3)(0 2 _ s _tC s Nt), (Ti 0 .99Sr 0 .oi
• the n-type semiconductor comprises (Tio.996Vo.oo4)(0 2 . s . t C s Nt), (Ti 0 .984Vo.oi6)(o2-s-tC s N t ), and/or (Tio.97oVo.o 3 )(0 2 _ s _tC s Nt).
• the heterogeneous material comprises a p-type semiconductors loaded onto an n-type semiconductor
• the heterogeneous material further comprises a second n-type semiconductor, wherein at least a portion of the second n-type semiconductor is ionic charge isolated from the p-type semiconductor.
• at least a portion of the second n-type semiconductor can be physically separated from the p-type semiconductor, ionic charge isolated, admixed and/or not loaded with the p-type semiconductor.
• the second n-type semiconductor can be any of those n-type semiconductors described elsewhere in this application.
• the ionic charge isolated or admixed n-type semiconductor can comprise Ce0 2 and/or plural phase n-type semi-conductor compounds.
• the plural phase n-type semi-conductor compounds comprise anatase phase and rutile phase compounds.
• the plural phase n-type semiconductor compounds can be titanium oxides.
• the anatase phase can be 2.5% to about 97.5%, 5% to about 95%, and/or about 10% to about 90%; and the rutile phase can be 97.5% to about 2.5%, 95% to about 5%, and/or about 10% to about 90%.
• a non-limiting example of a suitable material includes, but is not limited to a Ti0 2 mixture sold under the brand name P25 (83% Anatase phase Ti0 2 + 17% Rutile phase Ti0 2 ) sold by Evonik.
• the n-type semiconductor physically mixed with p-type loaded on WO3 can comprise Ce0 2 , Ti0 2 , SrTi0 3 and/or KTa0 3 .
• the n-type semiconductor physically mixed with p-type loaded on plural phase n-type semi-conductor compounds e.g., P25
• the n-type semiconductor physically mixed with p-type loaded on plural phase n-type semi-conductor compounds can comprise Ce0 2 , Ti0 2 , SrTi0 3 and/or KTa0 3 .
• the n-type semiconductor can be inorganic.
• the inorganic n-type semiconductor can be an oxide, such as a metal dioxide, including Ce0 2 , Ti0 2 , or the like.
• the n-type semiconductor can comprise Si0 2 , Sn0 2 , Al 2 0 3 , Zr0 2 , Fe 2 0 3 , Fe 3 0 4 , NiO, Nb 2 0 5 , and/or Ce0 2 .
• the n-type semiconductor can be RE k E m O n , wherein RE is a rare earth element, E is an element or a combination of elements, O is oxygen, and 1 ⁇ k ⁇ 2, 2 ⁇ m ⁇ 3, and 0 ⁇ n ⁇ 3.
• the n-type semiconductor can be RE p O q where RE can be a rare earth metal and p can be greater than or equal to 1 and less than or equal to 2, or can be between 1 and 2; and q can be greater than or equal to 2 and less than or equal to 3, or can be between 2 and 3.
• suitable rare earth elements include scandium, yttrium and the lanthanide and actinide series elements.
• Lanthanide elements include elements with atomic numbers 57 through 71. Actinide elements include elements with atomic numbers 89 through 103.
• the n-type semiconductor can be cerium.
• the n-type semiconductor can be CeO a (a ⁇ 2).
• the n-type semiconductor can be cerium oxide (Ce0 2 ).
• the n-type semiconductor can be a non-oxide.
• the non-oxide can be a carbide and/or nitride.
• the carbide can be silicon carbide.
• the mole ratio of physical mixture of the n-type semiconductor (e.g., Ce0 2 ) with p-type semiconductor loaded W0 3 can be 0-99% n-type semiconductor to 100%-1 % p-type semiconductor (Cu x O loaded W0 3 ).
• the mole ratio of physical mixture of the n-type semiconductor (e.g., Ce0 2 ) with p-type semiconductor loaded W0 3 can be 25 to 75% (and every integer in between) of n-type semiconductor to 75% to 25% (and every integer in between) of p-type semiconductor loaded n-type material (e.g., W0 3 ).
• the mole ratio of physical mixture of the n-type semiconductor (e.g., Ce0 2 ) with p-type semiconductor loaded W0 3 can be 40 to 60% (and every integer in between) of n-type semiconductor to 60% to 40% (and every integer in between) of p-type semiconductor loaded n-type material (e.g.,
• the heterogeneous material can further comprise a noble metal in ionic charge communication with the mixed valence oxide compound.
• the noble metal is loaded onto the n-type semiconductor.
• the noble metal can be, without limitation, rhodium, ruthenium, palladium, silver, osmium, platinum and or gold or mixtures thereof.
• the noble metal is platinum.
• a method for loading a mixed valence compound can be adding a p-type precursor to an attracting agent to make the surface charge of the n-type semiconductor more negative, wherein the p-type precursor comprises a copper cation complex.
• a method for loading a mixed valence compound comprises adding an attracting agent to the n-type compounds; and combining the n-type and p-type precursors to each other at a temperature below the doping temperature of the mixed valence compounds.
• the method further comprises the step of adding a dispersing agent to an n-type compound to more positively charge the surface of the n-type compound.
• a method for loading a mixed valence compound can be adding a dispersing agent to an n-type compound to more positively charge the surface of the n-type compound; adding a p-type precursor to the dispersing agent and n-type compound, wherein the p-type precursor comprises a copper cation complex; adding an attracting agent to the n-type compounds to make the surface charge of the n-type semiconductor more negative; and combining the dissimilarly charged materials with each other at a temperature below the doping temperature of the mixed valence compounds.
• the dispersing agent can be a strong acid. In some embodiments, the dispersing agent can be 4-7M HCI. In some embodiments, the dispersing agent is 6M HCI.
• a valence control material is added along with the dissimilarly charged materials to control the mixed valence oxides during the synthesis of the mixed valence oxides.
• the valence control material is a mild reducing agent.
• the valence control material can be at least one of a sugar, a hydrazide, an amino acid, and/or an amide.
• the amide can be urea.
• the sugar can be sucrose, fructose, and/or glucose.
• the sugar is glucose.
• the hydrazide can be Carbohydrazide, Oxalyl Dihydrazide, Maleic Hydrazide, Diformyl Hydrazine or Tetraformyl Trisazine.
• the amino acid can be at least one of the proteinogenic or natural amino acids.
• the amino acid can be an aliphatic amino acid (e.g., glycine, alanine, valine, leucine, and/or isoleucine).
• the amino acid can be a hydroxyl or sulfur containing amino acid (e.g., serine, cysteine, threonine and/or methionine).
• the amino acid can be cyclic (e.g., proline). In some embodiments, the amino acid can be aromatic (e.g., phenylalanine, tyrosine and/or tryptophan). In some embodiments, the amino acid can be basic (e.g., histidine, lysine, and/or arginine). In some embodiments, the amino acid is acidic or amide (e.g., aspartate, glutamate, asparagine and/or glutamine). In some embodiments the amino acid can be selenocysteine and/or pyrrolysine. In some embodiments the amino acid can be non- proteinogenic.
• the amino acid can be cyclic (e.g., proline). In some embodiments, the amino acid can be aromatic (e.g., phenylalanine, tyrosine and/or tryptophan). In some embodiments, the amino acid can be basic (e.g., histidine, lysine, and/or argin
• the non-proteinogenic amino acids include those not found in proteins (for example carnitine, GABA).
• the non- proteinogenic amino acids can be those in isolation by standard cellular machinery (for example, hydroxyproline and selenomethionine).
• the amino acid is soluble in water.
• the amino acid is soluble in water at 90°C.
• the amino acid is substantially entirely dissolved in water at 90°C.
• the term soluble has the ordinary meaning known to a person of ordinary skill in the art.
• the ratio of the mixed valence oxide compounds can be controlled by a method of loading the Cu onto the p-type semiconductor including adding the attracting agents.
• the attracting agents that can control the ratio of mixed valence oxide compounds can include a monosaccharide and a base compound.
• the monosaccharide can be glucose.
• the glucose can be D-glucose and/or L-glucose.
• the glucose to NaOH ratio can be 10% to 90% to 90% to 10%.
• Particular ratios can also include: 15% to 85%; 20% to 80%; 25% to 75%; 30% to 70%; 35% to 65%; 40% to 60%; 45% to 55%; 50% to 50%; 55% to 45%; 60% to 40%; 65% to 35%; 70% to 30%; 75% to 25%; 80% to 20%; and 85% to 15%.
• the base can be NaOH.
• Cu x O compound is valence controlled chemically.
• the attracting agent can be an agent that provides a sufficient amount of hydroxyl ions to bring the pH of the total solution between pH 8.0 to pH 9.0.
• the attracting agent can be a strong base.
• the attracting agent is a 4-7 M strong base.
• the attracting agent is 6 M NaOH.
• the p-type precursor can be a substantially sodium free compound.
• the substantially sodium free compound can be a copper cation complex.
• the copper cation complex can be Bis(Ethylenediamine) Copper (II) (BEDCull), Copper (II) tetra amine chloride, Copper (II) tetra amine sulfate, and/or Copper (II) tetra amine hydroxide and/or mixtures thereof.
• the compound can be Bis(Ethylenediamine) Copper (II). The structure of BEDCull is shown below:
• the doping temperature of the mixed valence compound is between 150°C to 700°C. In some embodiments, less than the doping temperature of the mixed valence compound is less than 175°C, less than 150°C, less than 125°C. In some embodiments, the mixing temperature is between 75°C to 125°C. In some embodiments the mixing temperature is 80°C; 85°C; 95°C; 100°C; 105°C; 1 10°C; 1 15°C; 120°C; or, 120°C.
• the precursor selected for the p-type semiconductors can be salts of chloride, acetate, nitrate, sulfate, carbonate, oxide, hydroxide, peroxide or combinations thereof.
• the described heterogeneous materials have photocatalytic activity.
• the heterogeneous materials can be anti-bacterial (light and dark); anti-viral; can decompose volatile organic compounds (VOC); and/or can discolor food additive dyes.
• Suitable non-limiting examples of food additive dyes include Natural Blue Colored powder (Color Maker, Anaheim, California, USA) and/or FD&C blue No. 2 synthetic food additive dye food additive dye (Synthetic blue colored powder, Chromatech, Inc., Michigan, USA).
• the heterogeneous materials described herein can also increase the durability (time of effectiveness) of photocatalytic materials.
• Those of ordinary skill in the art recognize ways to determine whether an heterogeneous material is anti-bacterial (light), e.g., after the heterogeneous material is exposed to visible light.
• anti-bacterial exposure results in at least a reduction of 10% (90% remains), at least 50% (50% remains), at least 99% (at least 1 % remains), at least 99.9% (at least 0.1 % remains) or at least 100% (0% remains).
• One example of determining whether the heterogeneous material is anti-bacterial (light) can be by assessing the amount of bacteria present; e.g., a decrease in the amount of bacteria present, after the heterogeneous material is contacted with the bacteria and exposed to visible light.
• the amount of bacteria present in the sample after exposing the sample for a predetermined time period can be assessed.
• the sample can be exposed for 15 minutes, 30 minutes, 1 hour, 2 hours, 5 hours, 7.5 hours, 10 hours, 12 hours 24 hours.
• the sample is exposed to 800 lux from a fluorescent light source or at least 5 mW/cm2 from a blue LED.
• anti-bacterial exposure results in at least a reduction of 10% (90% remains), at least 50% (50% remains), at least 99% (at least 1 % remains), at least 99.9% (at least 0.1 % remains) or at least 100% (0% remains).
• One example of determining whether the heterogeneous material is anti-bacterial (dark) can be by assessing the amount of bacteria present, e.g., reduction or decrease in the number of colonies present after the heterogeneous material is contacted with the bacteria without exposure to visible light.
• determining whether an heterogeneous material is anti-viral can be by assessing, e.g., an inhibition or reduction of the number of virus (phage) colonies. In one embodiment, determining whether the heterogeneous material is anti-viral can be by counting the number of viral colonies present over time after exposure to the heterogeneous material. In one embodiment, anti-viral exposure results in at least a reduction of 10% (90% remains), at least 50% (50% remains), at least 99% (at least 1 % remains), at least 99.9% (at least 0.1 % remains) or at least 100% (0% remains).
• determining whether an heterogeneous material decomposes volatile organic compounds can be by assessing the degradation of the organic compound under electromagnetic radiation, for example visible light.
• determining acetaldehyde degradation as a decrease or % of the initial degradation is an optional way to determine decomposition of volatile organic compounds; e.g., ranging from 0% to 90% over time; or, from 3 to 10 hours or 5 hours under an amount of visible light such as a blue light emitting LED of 455 nm having 270 mW/cm 2 power.
• the degradation is at least 50%, 60%, 70%, 80%, 90% or 100% of the initial amount of acetylaldehyde after exposure to the heterogeneous material.
• determining the discoloration of food additive dyes can be by the decrease or percentage of the initial amount of food dye additive over time.
• the food additive can be the natural anthocyanin food additive dye or an FDC food additive dye.
• the discoloration of food dye additives can be from 0% to 60% after 5 hours under a blue LED emitting at 455 nm with 45 mW/cm2 power.
• the degradation is at least 25%, 30%, 40% 50%, and/or 60% of the initial amount of the natural anthocyanin food additive dye after exposure to the heterogeneous material.
• the discoloration of food dye additives decreased from zero% to 60% after 5 hours under a blue LED emitting at 455 nm with 45 mW/cm2 power.
• the retention of antibacterial activity is after exposure to 85% relative humidity and 85°C for at least 7 days.
• a heterogeneous material comprising:
• a p-type semiconductor comprising a first metal oxide compound and a second metal oxide compound, wherein the first metal oxide compound and the second metal oxide compound have different oxidation states of the same metal, and wherein the p-type semiconductor has a p-type valence band;
• an n-type semiconductor having an n-type valence band which is deeper than the p- type valence band, wherein the n-type semiconductor is in ionic charge communication with the p-type semiconductor.
• Embodiment 2 The heterogeneous material of embodiment 1 , further comprising a noble metal in ionic charge communication with the first metal oxide compound and the second metal oxide compound.
• Embodiment 3 The heterogeneous material of embodiment 2, wherein the noble metal is rhodium, ruthenium, palladium, silver, osmium, platinum or gold.
• Embodiment 4 The heterogeneous material of embodiment 2 or 3, wherein the noble metal is loaded onto the n-type semiconductor.
• Embodiment s The heterogeneous material of embodiment 1 , 2, 3, or 4, further comprising a second n-type semiconductor, wherein at least a portion of the second n-type semiconductor is ionic charge isolated from the p-type semiconductor.
• Embodiment 6 The heterogeneous material of embodiment 5, wherein the second n- type semiconductor comprises a cerium oxide.
• Embodiment 7 The heterogeneous material of embodiment 6, wherein the cerium oxide is Ce0 2 .
• Embodiment 8 The heterogeneous material of embodiment 5, wherein the second n- type semiconductor comprises plural phase Ti0 2 .
• Embodiment 9 The heterogeneous material of embodiment 1 , 2, 3, 4, 5, 6, 7, or 8, wherein the first metal oxide compound comprises copper(l) and the second metal oxide compound comprises copper(ll), the first metal oxide compound comprises cobalt (II) and the second metal oxide compound comprises cobalt (III), the first metal oxide compound comprises Mn(ll) and the second metal oxide compound comprises Mn(lll), the first metal oxide compound comprises Fe(ll) and the second metal oxide compound comprises Fe(lll), or, the first metal oxide compound comprises and Ir(lll) and the second metal oxide compound comprises Ir(IV).
• Embodiment 10 The heterogeneous material of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, or 9, wherein the p-type semiconductor is loaded onto the n-type semiconductor.
• Embodiment 11 The heterogeneous material of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, or 9, wherein the p-type semiconductor is substantially uniformly dispersed onto the n-type semiconductor.
• Embodiment 12 The heterogeneous material of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, or 1 1 , wherein the p-type semiconductor is in the form of particles having a particle size of 100 nm or less.
• Embodiment 13 The heterogeneous material of embodiment 9, wherein the p-type semiconductor comprises copper(l) and copper(ll).
• Embodiment 14 The heterogeneous material of embodiment 13, wherein the p-type semiconductor comprises Cu x O.
• Embodiment 15 The heterogeneous material of embodiment 14, wherein the Cu x O is chemically valence controlled.
• Embodiment 16 The heterogeneous material of embodiment 9, wherein the ratio of copper(l):copper (II) is between 10:90 to 30:70.
• Embodiment 17 The heterogeneous material of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, or 16, wherein the p-type semiconductor is 0.001 to 10 wt% of the heterogeneous material and the n-type semiconductor is 90 to 99.999 wt% of the heterogeneous material.
• Embodiment 18 The heterogeneous material of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, or 17, wherein the n-type semiconductor is an oxide of cerium, tungsten, tantalum, tin, zinc, strontium, zirconium, barium, indium, or aluminum.
• Embodiment 19 The heterogeneous material of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, or 17, wherein the n-type semiconductor comprises Sn-Ti(0,C,N) 2 , , MgTi 2 0 5 , Ce0 2 , KTa0 3 , Ta 2 0 5 , Sn0 2 , W0 3 , ZnO, SrTi0 3 , BaTi0 3 , ZrTi0 4 , ln 2 Ti0 5 , AI 2 Ti0 5 ,
• Embodiment 20 The heterogeneous material of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, or 17, wherein the n-type semiconductor is AI 2 . x ln x Ti0 5 wherein 0 ⁇ x ⁇ 2.
• Embodiment 21 The heterogeneous material of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, or 17, wherein the n-type semiconductor is Zr 1 . y Ce y Ti0 4 wherein 0 ⁇ y ⁇ 1 .
• Embodiment 22 The heterogeneous material of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, or 17, wherein the n-type semiconductor is a titanium oxide having a valence band controlled through doping.
• Embodiment 23 The heterogeneous material of embodiment 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, or 17, wherein the n-type semiconductor is a titanium oxide doped with N, C, or both.
• Embodiment 24 The heterogeneous material of embodiment 22, wherein the n-type semiconductor is a titanium oxide comprising a compound represented by the formula
• M is Sn, Ni, Sr, Ba, Fe, Bi, V, Mo, W, Zn, Cu, or a combination thereof;
• r is from 0 to 0.25;
• s is from 0.001 to 0.1 ;
• t is from 0.001 to 0.1 .
• Embodiment 25 The heterogeneous material of embodiment 24, comprising
• Embodiment 26 The heterogeneous material of embodiment 16, wherein the n-type semiconductor comprises (Tii. r M r )(0 2 . s . t C s N t ), wherein:
• M is Sn
• r is from 0 to 0.25;
• s is from 0.001 to 0.1 ; and t is from 0.001 to 0.1.
• Embodiment 27 The heterogeneous material of embodiment 26, wherein r is greater than 0.
• Embodiment 28 The heterogeneous material of embodiment 26, wherein r is 0, and the semiconductor comprises a rutile phase and an anatase phase.
• Embodiment 29 The heterogeneous material of embodiment 16, wherein the n-type semiconductor is a tin oxide.
• Embodiment 30 A method of decomposing a chemical compound, comprising exposing the chemical compound to a photocatalyst comprising the homogeneous material of any of embodiments 1 -29 in the presence of light.
• Embodiment 31 The method of embodiment 30, wherein the chemical compound is a pollutant.
• Embodiment 32 A method of killing a microbe, comprising exposing the microbe to a photocatalyst comprising the homogeneous material of any of embodiments 1-29 in the presence of light.
• Example 1(a) Synthesis of an n-type semiconductor (Ex-1)
• Combustion synthesized Ti(0,C,N) 2 :Sn (6 g) was mixed with 6M HCI (60 mL) at 90°C for 3 hours in a water bath while stirring. The mixture was then cooled down to room temperature, filtered through 0.2 micron membrane filter paper, washed with 100 to 150 mL of deionized water (Dl) water, and finally dried at room temperature overnight for between 10 to 15 h.
• 6M HCI 60 mL
• Dl deionized water
• Example 1(b)' Comparative Example 0 (CE-0)
• Total weight percent of Cu as 0.25wt.%CuO + 0.125wt.% Cu 2 0 was physically mixed with Sn-Ti(OCN) 2 photocatalyst by hand using mortar and pestle in 5-10 mL amount of methanol. The mixing was continued until all the methanol had evaporated.
• CE-1 Ti(CNO) 2 :Sn
• Example 1 (a) was prepared in a manner similar to that of Example 1 (a), except that no loading of Cu x O (step A only) was performed resulting in unloaded Ti(CNO) 2 :Sn (no Cu x O).
• Ex-1 A was prepared in a manner similar to that of Example 1 (b) above, except that 25 mg instead of 50 mg of NaOH and 125 mg instead of 250 mg of glucose were used.
• Example 1(d)' was prepared in a manner similar to that of Example 1 (b) above, except that 25 mg instead of 50 mg of NaOH and 125 mg instead of 250 mg of glucose were used.
• Example 1(d)' was prepared in a manner similar to that of Example 1 (b) above, except that 25 mg instead of 50 mg of NaOH and 125 mg instead of 250 mg of glucose were used.
• Example 1(d)' Comparative Example 2' (Ex-1 B)
• Ex-1 B was prepared in a manner similar to that of Example 1 (b) above, except that the weight fraction of Copper to processed Ti(0,C,N) 2 :Sn (1g) was 0.005.
• Ex-2 (Plasma W0 3 ) and Ex-3 (commercial GTP W0 3 ) were prepared in a manner similar to that of Ex-1 above, except that the same molar amounts of Plasma W0 3 or commercial GTP-WO3 were used instead of Ti(0,C,N) 2 :Sn photocatalyst; NaOH was not added to the reaction mixture and the glucose amount was 125 mg instead of 250 mg.
• Plasma W0 3 was made in a similar manner to that described in U.S. Patent Application No 13/738,243, filed January 10, 2013 which is incorporated by reference herein for its teachings regarding the same.
• GTP W0 3 was purchased from Global Tungsten & Powder (Towanda, PA, USA) and used without additional purification or annealing.
• Ex-4, Ex-5, Ex-6 and CE-2 were prepared in a manner similar to that of Ex-1 , except that the same molar amounts of Ce0 2 were used instead of Ti(0,C,N) 2 :Sn.
• the loading conditions were modified as follows: Ex-4: aqueous solution of NaOH (25 mg) and glucose (125 mg); Ex-5: without glucose; Ex-6: the concentration of glucose (62.5 mg) and NaOH (25 mg).
• CE-2 is analogous to CE-1 , except that CE-2 is an equivalent unloaded molar amount (to Ti(0,C,N) 2 :Sn ) of Ce0 2 (Sigma Aldrich, St. Louis, MO, USA). Ce0 2 was used as received from the vendor without additional purification or annealing.
• Ex-7 was prepared in a manner similar to that of Ex-1 above, except that the same molar amount of insulator, Al 2 0 3 was used instead of Ti(0,C,N) 2 :Sn, 25 mg of NaOH was used, and 125 mg of glucose was used.
• the Cu x O loading was 1 wt% Cu with respect to Al 2 0 3 .
• CE-3 is analogous to CE-1 , except that CE-3 is an equivalent unloaded molar amount (to Ti(0,C,N) 2 :Sn ) of Al 2 0 3 .
• Al 2 0 3 was used as received from the vendor without additional purification or annealing.
• Ex-8 was prepared in a manner similar to that of Ex-1 above, except that the same molar amount of n-type UV active photocatalyst, Ta 2 0 5 was used instead of Ti(0,C,N) 2 :Sn, 25 mg of NaOH and 125 mg of glucose were used.
• the Cu x O loading was 1 wt% Cu with respect to Ta 2 0 5 .
• CE-4 is analogous to CE-1 , except that CE-4 is an equivalent unloaded molar amount (to Ti(0,C,N) 2 :Sn ) of Ta 2 0 5 (Sigma Aldrich, St. Louis, MO, USA). Ta 2 0 5 was used as received from the vendor without additional purification or annealing.
• Ex-9 was prepared in a manner similar to that of Ex-1 above, except that the same amount of n-type UV active photocatalyst, Sn0 2 was used instead of Ti(0,C,N) 2 :Sn.
• the CuxO loading was 1 wt% Cu with respect to Sn0 2 .
• the nanosize Sn0 2 US Research Nanomaterial, Houston, TX, USA
• the nanosize Sn0 2 had been annealed at 900°C in a box furnace in air for 1 h. It was then soaked in 6M HCI aqueous solution as in Ex-1.
• the amount of NaOH was 25 mg and the amount of glucose used was 125 mg.
• Ex-1 1 the amount of NaOH was 75 mg and the amount of glucose was 375 mg.
• CE-4A is analogous to CE-1 , except that CE-4A is an equivalent unloaded molar amount (to Ti(0,C,N) 2 :Sn) of Sn02. With varying amounts of NaOH and glucose while loading fixed amount of 1 wt% Cu with respect of Sn0 2, different appearances of body color resulted.
• Ex-12 was prepared in a manner similar to that of Ex-1 B above. Loading of Cu x O was performed on rutile Ti0 2 (Tayca, Inc. Osaka, JP) except that 25 mg instead of 50 mg of NaOH and 125 mg instead of 250 mg of glucose were used.
• CE-5 is analogous to CE-1 , except that CE-5 is an equivalent unloaded molar amount (to Ti(0,C,N) 2 :Sn) of Rutile Ti02 (Tayca, Inc. Osaka, JP). Rutile Ti02 was used as received from the vendor without additional purification or annealing.
• Ex-14 to Ex-17 were prepared in a manner similar those described above except that different amounts of [Pt(NH 3 ) 4 ]CI 2 ] and/or lrCI 3 /lr0 2 were dissolved in the 15 mL of RO water. See Table 1 as follows:
• CE-6 is analogous to CE-1 , except that CE-5 is an equivalent unloaded molar amount (to Ti(0,C,N) 2 :Sn ) of W0 3 (Global Tungsten Powder, PA, USA). W0 3 was used as received from the vendor without additional purification or annealing.
• Example 1(1) Synthesis of an n-type semiconductor (Ex-18)
• MgTi205 synthesis 2.663 g Mg(N0 3 ) 2 -6H 2 0 (Sigma Aldrich, St. Louis, MO, USA), 5 g ammonium nitrate (Sigma Aldrich, St. Louis, MO, USA), 1.5g Urea (Sigma Aldrich, St. Louis, MO, USA) and 10mL of Titanium(IV) bis(ammonium lactate)hydroxide (titanium lactate, [Tyzor LA]) (Sigma Aldrich, St. Louis, MO, USA) were dissolved in about 10 mL of Dl water in 250 mL of low-form Pyrex beaker.
• the resulting mixture was then heated at 350°C for 20 minutes in a preheated muffle furnace under ambient atmosphere (room atmosphere) and pressure conditions.
• the resulting powder was placed in the preheated muffle furnace and then annealed at 600°C under ambient conditions for about 30 minutes.
• Cu x O loaded MgTi 2 0 5 Cu x O was loaded onto the MgTi 2 0 5 in a manner similar to that described in Example 1 (b), except that in this preparation, no HCI preparation step was used.
• the NaOH preparation step used was similar to that described in Example 1 (b).
• the weight fraction of copper to MgTi 2 0 5 was 0.01.
• 10mL aqueous solution of CuCI 2 *2H20 (26.8 mg) was stirred with 1g of MgTi 2 0 5 at about 90°C for about 1 h.
• 1.5mL of aqueous solution containing NaOH(25 mg) and glucose (125 mg) was added to the reaction mixture at about 90°C while stirring.
• the plural phasic n-type semiconductor was loaded onto CuxO in a manner similar to that in Example 1 (b).
• the weight fraction of copper to plural phasic n-type semiconductor (87% anatase phase Ti02/13% rutile phase Ti0 2 sold under the brand name "P25" [EvoniK Degussa, NJ, USA]) was 0.01.
• 15mL aqueous solution of CuCI 2 -2H 2 0 (26.8 mg) was stirred with 1g of P25 at about 90°C for 1 h.
• 1.5mL of aqueous solution containing NaOH(25mg) and glucose (125mg) was added to the reaction mixture at about 90°C while stirring.
• Comparative Example CE-7 was prepared in a manner similar to Example 1 (m) except that 0.25wt.%CuO+0.125wt.%Cu2O was physically mixed with 0.625wt% P25 in methanol (5-1 OmL) by hand until the methanol is substantially all evaporated.
• Example 1(o). (Ex-19 (AgVW0 6 ))
• Example 1(p). (Ex-20 (AgCa2Zn 2 V 3 0i2))
• the anatase Ti02 observed in the XRD pattern and visible absorption due to the anatase phase confirmed the loading of Ti(0,C,N) 2 :Sn, Ce0 2 , and Al 2 0 3 on the substrate.
• the loaded Cu x O had absorption in the longer wavelength side of absorption edge of semiconductors and if the loaded Cu x O had a mixture of CuO and Cu 2 0, then their characteristics absorptions between 600 and 800 nm and 500 and 600 nm respectively would have been observed, in addition to absorption of loaded Cu x O.
• Ex-1A (130 mg), as prepared according to the methods described earlier in this disclosure, was added to 1.04 ml Dl water in order to make a coating solution which was 10 wt% solid materials in water. The resulting dispersion was homogenized using an ultrasonic homogenizer. A glass substrate (50 mm x 75 mm) was coated with the prepared resultant by using a spin coater (1200 rpm/ 40 sec). The coated substrate was heated for 2 minutes at 120°C. Another slide was prepared in the same manner except that CE-1 (130 mg) was used instead of Ex-1A.
• the spin coated glass slides were heated at 120°C on a hot plate under full spectrum irradiation by a Xe (xenon) lamp (lamp power output 300 W) for 1 hour. Each slide was then sealed in a separate 5 L Tedlar bag under vacuum, followed by injecting 3L of ambient air and 80 ml_ of 3500 ppm acetaldehyde. Each bag was lightly massaged for 2 minutes by hand then placed in the dark for 15 min. The acetaldehyde concentration was estimated by Gas Chromatography-Flame Ionization Detector (GC-FID) to be at 80 ⁇ 2 ppm. Each Tedlar bag containing a sample was placed back in the dark for 1 hour.
• GC-FID Gas Chromatography-Flame Ionization Detector
• FIG. 9 is a graph illustrating Ex-1A VOC performance data. The graph shows that generally when Ti(CNO) 2 :Sn is combined with Cu x O (Ex-1A), performance is improved when compared to bare Ti(CNO) 2 :Sn (CE-1 ).
• Substrate (1 " x 2" glass slide) was prepared by sequential application of 70% IPA (Isopropyl Alcohol) and 100% ethanol (EtOH) and then dried in air.
• Ex-1 B was dispersed in 100% EtOH at 2mg/ml_ concentration and then 100 uL of the suspension was applied to the substrate, and then dried. The application process was repeated 5 times to attain 1 mg of Ex-1 B on the substrate. The substrate was then dried at room temperature. The coated substrates were placed in a glass dish with a water soaked filter paper for maintaining moisture, and glass spacers were inserted between the substrate and the filter paper to separate them.
• E. coli (ATCC 8739) was streaked onto a 10 cm diameter petri dish containing 20 ml of LB (lysogeny broth/ luria broth) agar, and incubated at 37°C overnight. For each experiment, a single colony was picked to inoculate 3ml_ nutrient broth, and the inoculated culture was incubated at 37°C for 16 hours to create an overnight culture (-109 cells/mL). A fresh log-phase culture of the overnight culture was obtained by diluting the overnight culture x100, inoculating another 5 cm petri dish with LB agar and incubating at 37°C for 2.5 hr.
• LB lysogeny broth/ luria broth
• the fresh culture was diluted 50x with 0.85% saline, which gave a cell suspension of 2 x 10 6 cells/mL.
• 50 ⁇ of the cell suspension was pipetted onto each deposited glass substrate.
• a sterilized (in 70% and then 100% EtOH) plastic film (20 mm x 40 mm) was placed over the suspension to spread evenly under the film.
• the specimen was kept in the dark (Cu x 0 2 - Dark) or then irradiated under blue LED light (455 nm, 10 mW/cm2) (Cu0 2 -light).
• the specimen was placed in 10mL of 0.85% saline and vortexed to wash off the bacteria.
• the wash off suspension was retained, then serially diluted using 0.85% saline, and then plated on LB agar and incubated at 37°C overnight to determine the number of viable cells in terms of CFU/Specimen.
• FIG 10 also shows the property of Cu 1+ after loading on Ce0 2 that complete killing of E-coli is observed in 1 h for dark as well as under 10 mW/cm2 blue LED of 455 nm light. Therefore, Cu x O loaded Ce0 2 is a good functional material for E-Coli killing.
• Example 4B
• Ex-1 powder was prepared as described in Example 1. The powder was then kept in the dark at 85% relative humidity and 85°C for a period of 7 days. The slide[s] were then prepared and tested for antibacterial activity in the same manner as described in Example 4A. The results are shown in FIG.12A. The results show that even after exposure to 85% relative humidity and 85°C for a period of 7 days, Ex-1 demonstrated retained photocatalytic activity.
• Ex-7 powder was prepared as described above. The powder was then kept in the dark at 300°C for 20 minutes. The slide[s] were then prepared and tested for antibacterial activity in the same manner as described in Example 4A. The results are shown in FIG.12B. The results show that even after exposure to 300°C for 20 minutes, Ex-7 retained photocatalytic activity.
• the degradation of the resulting blue colored solution was measured at 1 h, 3h and 5h by monitoring its concentration using UV-Vis absorption spectroscopy (Cary-50, Spectrophotometer Agilent Technologies, Santa Clara, CA, USA). The concentration was calculated as intensity of the peak at 600 nm. The results are shown in FIGURE 13. Table 2 below compares the final degradation results of the four photocatalytic materials.
• a clean petri dish was wiped with ethanol and the inside surface of the dish was ionized with a plasma device for 1 to 2 minutes.
• the homogeneous sample of each compound was poured into the treated petri dish and then heated at 120°C while swirling to increase uniform distribution of the sample as it dried. After the sample had dried, the Petri Dish was placed under a UV Lamp (300W) for 1 hour.
• Each petri dish was then sealed in a separate 5 L Tedlar bag under vacuum, followed by injecting 3L of ambient air and 80 mL of 3500 ppm acetaldehyde. Each bag was lightly massaged for 2 minutes by hand then placed in the dark for 15 min.
• acetaldehyde concentration was estimated by Gas Chromotagraphy-Flame Ionization Detector (GC-FID) to be at 80 ⁇ 2 ppm.
• GC-FID Gas Chromotagraphy-Flame Ionization Detector
• Tedlar bag containing a sample was placed back in the dark for 1 hour.
• the slide/Tedlar bag was exposed to array blue LED of 455 nm with light intensity of 0.656 mW/cm 2 .
• a sample was collected every 30 minutes by an automated injection port of GC-FID and the amount of remaining acetaldehyde was estimated at subsequent 30 minute intervals. The results are shown in Table 3 below.
• FIG.14 shows the decomposition rate of acetylaldehyde (Ct/Co) with W0 3 (commercial GTP) (CE-6), 0.05 mol% Pt loaded W0 3 (Ex-13), 0.1 mol% Ir0 2 loaded W0 3 (Ex-16) and both 0.05 mol% Pt and 0.1 mol% Ir02 loaded W0 3 (two times) (Ex-17).
• W0 3 commercial GTP
• CE-6 0.05 mol% Pt loaded W0 3
• Example-16 0.1 mol% Ir0 2 loaded W0 3
• Ir0 2 0.1 mol% Ir02 loaded W0 3
• Substrate (1 " x 2" glass slide) was prepared by sequential application of 70% IPA (Isopropyl Alcohol), 100% EtOH and then dried in air. Ex-1 B was dispersed in 100% EtOH at 2mg/mL concentration and then about 100 uL of the suspension was applied to the substrate, and then dried. The application process was repeated 5 times to attain about 1 mg of Ex-1 B on the substrate. The substrate was then dried at room temperature. The coated substrates were placed in a glass dish with a water soaked filter paper for maintaining moisture. Glass spacers were inserted between the substrates and the filter paper to separate the substrates from the filter paper.
• 70% IPA Isopropyl Alcohol
• E. coli (ATCC 8739) was streaked onto a 5 cm diameter petri dish containing about 25 ml of LB agar, and incubated at about 37°C overnight. For each experiment, a single colony was picked to inoculate about 3 mL nutrient broth, and the inoculated culture was incubated at about 37°C for about 16 hours to create an overnight culture ( ⁇ 10 9 cells/mL). A fresh log-phase culture of the overnight culture was obtained by diluting the overnight culture x100, inoculating another 5 cm petri dish with LB agar and then incubated at about 37°C for about 2.5 hr.
• the fresh culture was diluted 50x, which gave a cell suspension of about 2 x 10 6 cells/mL. 50uL of the cell suspension was pipetted onto each glass substrate. A sterilized (in 70% and then 100% EtOH) plastic film (20 mm x 40 mm) was placed over the suspension to spread the suspension evenly under the film. At chosen time point, e.g., about 30 minute increments, the specimen was placed in 10ml_ of 0.85% saline and vortexed at 3200 rpm for about 1 min to wash off the bacteria. The wash off suspension was serially diluted using 0.85% saline, and plated on LB agar and incubated at about 37°C overnight to determine the number of viable cells in terms of CFU/Specimen.
• Counting was performed by visual inspection and the result multiplied by the dilution factor to arrive at the determined number.
• the specimen was then irradiated and positioned under a 455 nm blue light emitting LED to provide about 45 mw/cm 2 to the specimen. The results are shown in FIG. 19.
• Example 6A The anti-bacterial properties of CE-7 and Ex-7A were determined as described in Example 6A, except that molar equivalent amount of CE-7 and Ex-7A were used instead of Ex-1 B. The results are shown in FIGs 17 (CE-7) and 18 (Ex-7A).
• the pellet was resuspended in 1 mL of Dl water, and mixed with 4 mL of Dl water in a 20 mL clear glass vial with lid. 5 mL of methanol was added, bringing the total volume in the vial to -10 mL.
• a magnetic stir bar (1/2" x 1/8", disposable) was added to the vial, and placed on a stir plate (1000 rpm).
• A300 W Xenon lamp (Oriel 6881 1 ) was placed about 15 cm away from the vial wall. The irradiation lasted 1 hour in a vented hood, and there was negligible temperature change in the vial during the process.
• Aqueous combustion method was used to prepare Boron Doped W03 with Epsilon Phase.
• the body color of the powder appeared orange-yellow in color and it was confirmed by comparision with powder XRD pattern (Fig.1 ) with a standard epsilon W0 3 x-ray diffraction (ICFF PDF card number 01-087-2404)
• Fig.1 Powder XRD pattern (right).

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