WO2005014170A1

WO2005014170A1 - Photocatalyst material being activated by visible light, raw material for the same and method for producing the same

Info

Publication number: WO2005014170A1
Application number: PCT/JP2004/011235
Authority: WO
Inventors: Takeshi Morikawa; Kenichi Suzuki; Hideyuki Masaki; Takeshi Ohwaki; Yasunori Taga
Original assignee: Kabushiki Kaisha Toyota Chuo Kenkyusho
Priority date: 2003-08-08
Filing date: 2004-08-05
Publication date: 2005-02-17
Also published as: CN100431706C; CN1812837A; JPWO2005014170A1; JP3885825B2

Abstract

A method for producing a photocatalyst material, which comprises a step of adding at least one of nitrogen, sulfur, carbon and phosphorus to a metal oxide or a precursor thereof, and a step of incorporating at least one of vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum and a lanthanoid onto the surface or into the interior of the metal oxide or a precursor thereof, in the state wherein it is bound with an oxygen atom or in the state of a hydroxide or a salt.

Description

Specification

Photocatalyst having visible light activity, raw material thereof and method for producing the same

Technical field

The present invention relates to a photocatalyst having photocatalytic activity under irradiation with visible light and a method for producing the same.

Background art

[0002] Metal oxides such as titanium oxide, tin oxide, and zinc oxide generate electrons and holes by photoexcitation when irradiated with ultraviolet light, and act as photocatalysts that exhibit strong reducing power and oxide power. This photocatalyst is widely used for decomposition, purification, deodorization, sterilization, and the like of harmful substances.

[0003] A technique has been disclosed for increasing the photocatalytic activity in the ultraviolet region by supporting and fixing metals such as iron and copper and their oxides on the surface of a metal oxide having photocatalytic activity in the ultraviolet region. (For example, JP-A-6-39285, JP-A-7-303835, JP-A-9-227319, JP-A-11-244709, JP-A-2000-95976, JP-A-2000-95 205103, JP-A-2003-135974, JP-A-2003-190811, etc.).

[0004] On the other hand, in crystals of metal oxides such as titanium oxide, tin oxide, and zinc oxide, a part of the oxygen is replaced by nitrogen, sulfur, carbon, and phosphorus, or nitrogen, High photocatalytic activity not only under ultraviolet light but also under visible light irradiation by doping sulfur, carbon, and phosphorus, and by including nitrogen, sulfur, carbon, and phosphorus in the grain boundaries of the polycrystalline aggregate. (Eg, Japanese Patent Application Laid-Open No. 2000-205103).

[0005] However, the conventional photocatalyst has a lower absorbance in the visible light region than in the ultraviolet light region, and the quantum efficiency ratio is a guide to the light use efficiency under ultraviolet light irradiation and under visible light irradiation. However, the ultraviolet light Z visible light was about 5Zl, and a sufficient reaction rate could not be obtained in the visible light region. Therefore, when these photocatalysts are used for furniture, wall materials, lighting equipment, appliances, bathroom members, washbasin supplies, kitchenware, disposable paper, automobile interior parts, other indoor parts, dental materials, etc. I couldn't get a reaction.

[0006] Further, in the above-described conventional technology, it is necessary to enhance the photocatalytic activity of a metal oxide in an ultraviolet light region. Despite this, the photocatalytic activity of the photocatalyst having activity in the visible light region could not be increased. In addition, the technique of supporting a noble metal such as platinum (Pt) on a photocatalyst has a problem that the raw material is expensive.

Disclosure of the invention

[0007] The present invention provides a metal oxide containing at least one of nitrogen, sulfur, carbon, and phosphorus on a surface or inside of a metal oxide containing vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, A photocatalyst that exhibits photocatalytic activity under visible light irradiation, containing at least one of niobium, molybdenum, and a lanthanoid in a state of being bonded to an oxygen atom, in a state of a hydroxide, or in a state of a salt.

[0008] Here, in the photocatalyst of the present invention, it is preferable that the metal oxide is at least one oxide of titanium, tin, and zinc.

[0009] In the photocatalyst of the present invention, the metal oxide preferably contains at least one of nitrogen and sulfur. Further, the content thereof is desirably within 0.01 to 13% of the whole in terms of the atomic number ratio. More preferably, it is within the range of 0.01% to 2.00%.

[0010] Further, in the photocatalyst of the present invention, vanadium, manganese, chromium, iron, and vanadium having a valence lower than the maximum valence that can stably exist as an oxide in the atmosphere.

, Cobalt, copper, yttrium, zirconium, niobium, molybdenum, and lanthanoids.

[0011] In the photocatalyst of the present invention, vanadium, manganese, chromium, iron, cobalt

, Copper, yttrium, zirconium, niobium, molybdenum, lanthanide the 0.01 weight ^_0/0 or more

It is preferable to contain it in a range of 6.0% by weight or less.

[0012] Further, the photocatalyst of the present invention contains at least one of iron and copper, and X

709 eV or more and 710 eV or less and 932 eV or more in 2p shell spectra by PS 93

It is preferable to have the largest peak below 3 eV.

The photocatalyst of the present invention contains at least one of Cu 上記 and Fe〇.

2

Is preferred.

Further, in the photocatalyst of the present invention, the iron or copper nitrate, carbonate, sulfate, phosphorus It preferably contains at least one of acid salts, acetates and chlorides.

[0015] In the photocatalyst of the present invention, it is preferable that the primary particle diameter is 5 nm or more and 50 nm or less.

[0016] Another embodiment of the present invention relates to a metal oxide containing at least one of nitrogen, sulfur, carbon, and phosphorus, and vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, and molybdenum. And at least one salt or ion of a lanthanoid.

Another embodiment of the present invention relates to a method for preparing a metal oxide or a precursor thereof, an ammonium salt or aqueous ammonia, vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum, and a lanthanoid. It is a photocatalyst raw material containing at least one salt or ion.

Another embodiment of the present invention relates to a metal oxide or a precursor thereof, at least one of urea, thiourea, urine dioxide, and thiourea dioxide, and vanadium, manganese, chromium, iron, cobalt, and copper. A photocatalyst raw material containing at least one salt or ion of, yttrium, zirconium, niobium, molybdenum, and lanthanoid.

Here, in the photocatalyst raw material of the present invention, the metal oxide is preferably titanium oxide.

[0020] Further, in the above photocatalyst raw material of the present invention, the precursor of the metal oxide is titanyl sulfate, titanium sulfate, titanium oxide hydroxide, titanium hydroxide, titanium alkoxide, metatitanic acid, orthotitanium. It preferably contains at least one of an acid, hydrated titanium oxide, titanium chloride and an organic titanium compound.

[0021] Another embodiment of the present invention provides a first step of adding at least one of nitrogen, sulfur, carbon, and phosphorus to a metal oxide or a precursor thereof, and a step of adding the metal oxide or the precursor thereof. Contains at least one of vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum, and lanthanoid on the surface or in the state of being bonded to an oxygen atom, hydroxide or salt And a second step of producing a photocatalyst having photocatalytic activity under visible light irradiation.

[0022] Another embodiment of the present invention provides vanadium, manganese, chromium, iron, cobalt Metal, copper, yttrium, zirconium, niobium, molybdenum, and lanthanoids in the form of a metal oxide or hydroxide containing at least one of them bonded to an oxygen atom, hydroxide, or salt; And a method for producing a photocatalyst having photocatalytic activity under visible light irradiation to which at least one of phosphorus and phosphorus is added.

[0023] Another embodiment of the present invention provides vanadium, manganese, chromium, iron, cobalt, copper on the surface or inside of a metal oxide or a precursor thereof to which at least one of nitrogen, sulfur, carbon, and phosphorus is added. Manufacture of a photocatalyst having photocatalytic activity under visible light irradiation in which at least one of yttrium, zirconium, niobium, molybdenum, and lanthanoid is contained in a state of being bonded to an oxygen atom, in a hydroxide state or in a salt state. Is the way.

[0024] Another embodiment of the present invention relates to a metal oxide containing at least one of nitrogen, sulfur, carbon, and phosphorus, and vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, and molybdenum. A first step of mixing at least one salt of a lanthanoid, and a second step of heating the mixture at a temperature of 80 ° C. or more and 600 ° C. or less under visible light irradiation. This is a method for producing a photocatalyst having:

[0025] Another embodiment of the present invention provides a first step of heating a metal oxide or a precursor thereof in an atmosphere containing ammonia gas, a product obtained in the first step, vanadium, A second step of mixing at least one of manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum, and a lanthanoid; and mixing the mixture obtained in the second step with 80 °. A method for producing a photocatalyst having photocatalytic activity under irradiation with visible light, comprising: a third step of heating at a temperature of C to 600 ° C.

[0026] Another embodiment of the present invention relates to a method for preparing a metal oxide or a precursor thereof, which includes urea, thiourea, urine dioxide, thiourea dioxide, melamine, guanidine, cyanuric acid, biuret, peracyl, and other amide / imide. A first step of heating a mixture of at least one of the above, and the product obtained in the first step, and vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum, a lanthanoid. And a third step of heating the mixture obtained in the second step at a temperature of not less than 80 ° C. and not more than 600 ° C. This is a method for producing a photocatalyst having photocatalytic activity under irradiation with visible light. Here, in the present invention, the precursor of the metal oxide is titanyl sulfate, titanium sulfate, hydrous titanium oxide, titanium hydroxide, titanium alkoxide, metatitanic acid, orthotitanic acid, hydrated titanium oxide, chloride It is preferable that at least one of titanium and an organic titanium compound is used.

[0028] Another embodiment of the present invention provides a first step of mixing a metal oxide precursor and a nonmetal sulfide or an organic sulfur compound having an SH group; In the second step, the product obtained in the first step is heated, and the product obtained in the second step is mixed with vanadium, manganese, chromium, iron, cobalt, copper, yttrium, and zirconium. A third step of mixing at least one of dium, niobium, molybdenum, and a lanthanoid; and heating the mixture obtained in the third step at a temperature of 80 ° C to 600 ° C. And a fourth step of producing a photocatalyst having photocatalytic activity under visible light irradiation.

Here, in the present invention, it is preferable that the metal oxide precursor contains at least one of a metal organic compound, a halide, and an oxyhalide.

Further, in the present invention, it is preferable that the metal oxide is titanium oxide.

Brief Description of Drawings

FIG. 1 is a view showing a flowchart of a method for producing a photocatalyst according to an embodiment of the present invention.

FIG. 2 is a view showing a result of XPS measurement of the photocatalyst obtained in Example 1.

FIG. 3 is a view showing a result of XPS measurement of the photocatalyst obtained in Example 2.

FIG. 4 is a graph showing a decrease in the concentration of acetoaldehyde due to irradiation with visible light.

FIG. 5 is a graph showing an increase in carbon dioxide concentration due to irradiation with visible light.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a flowchart of a process for producing a photocatalyst having photocatalytic activity under irradiation with visible light in the present embodiment.

In step S10, a visible light responsive metal oxide is generated as in the conventional case. Metal acid The oxides can be titanium oxide (Ti-10), tin oxide (Sn-0), and zinc oxide (Zn-〇). At this time, by adding at least one of nitrogen (N), sulfur (S), carbon (C), and phosphorus (P) to these metal oxides, a metal exhibiting photocatalytic activity under visible light irradiation. It can be a group oxide.

[0034] At this time, nitrogen, sulfur, carbon, and phosphorus are substituted with oxygen atoms in the crystal of the metal oxide, doped with gaps in the lattice of the crystal of the metal oxide, and in the crystal of the metal oxide. It is considered that the inclusion of at least one of the states in which the grain boundaries are doped makes it possible to exhibit photocatalytic activity under visible light irradiation. The case where the above-mentioned nitrogen, sulfur, carbon and phosphorus substitute oxygen atoms, and the case where these are further bonded to a hydrogen atom or an oxygen atom are also included. That is, taking nitrogen (N) as an example, N-H and N-O may be used, and N may substitute for an oxygen atom position.

In particular, when the metal oxide is titanium oxide, it preferably has at least one of anatase, rutile, wurtzite, and amorphous structures. In particular, when it shows an anatase type or a rutile type as measured by X-ray diffraction, it exhibits high photocatalytic activity under visible light irradiation.

[0036] Titanium oxide containing nitrogen exhibits high photocatalytic activity under visible light irradiation when a peak is observed around 400 eV in a spectrum measured by X-ray photoelectron spectroscopy (XPS). In particular, it is preferable that a peak is observed around 396 eV to 397 eV. At this time, it is considered that the titanium atom of the titanium oxide and the contained nitrogen atom have a chemical bond. For example, it is considered that a site of an oxygen atom has a structure in which a part of the site is replaced by a nitrogen atom.

[0037] The metal oxide can be obtained by heating the metal oxide or its precursor and the nitrogen compound while stirring and mixing. Here, titanium oxide, tin oxide, or zinc oxide can be used as the metal oxide. Examples of the precursor of the metal oxide include titanium compounds such as titanyl sulfate, titanium sulfate, titanium chloride, and organic titanium compounds; tin sulfate compounds such as tin sulfate and tin chloride; or zinc compounds such as zinc sulfate and zinc chloride. Can be used. As the nitrogen compound, urea, thiourea, urea dioxide, thiourea dioxide, melamine, guanidine, cyanuric acid, biuret, and perasinole can be used. This When a precursor of these metal oxides and a nitrogen compound are used, the heating is preferably performed in a temperature range of 200 ° C to 500 ° C. In addition, if the reaction residue on the surface is washed with an acid such as sulfuric acid, hydrochloric acid, or nitric acid, or an alkali such as sodium hydroxide or ammonia water or high-temperature steam after the heat treatment, higher activity may be obtained in some cases. It is better to process according to.

[0038] The heating may be performed on the slurry mixed and stirred with the aqueous solution of the metal salt in step S14.

Further, a metal organic compound, a halide or an oxyhalide is dissolved in a solvent, an organic sulfur compound is added to obtain a precursor, and the precursor is heated in an atmosphere containing oxygen to thereby form a metal oxide. Can be obtained.

Here, as the metal organic compound, a metal alkoxide acetyl acetonate or the like can be used. For example, in the case of titanium, tetraisopropoxy titanium can be used as the organic compound. In addition, titanium butoxide, tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate, tetraoctyl titanate, titanium chelate, titanium acetinoleacetonate, titanium octaylene glycolate, titanium tetraacetyl acetate toner, titanium ethyl Acetate acetate, titanium acylate, polyhydroxytitanium stearate, titanium ratate, titanium triethanolaminate tetra i-propoxytitanium, di_i_propoxy 'bis (ethynoleacetoacetate) titanium, di_i_propoxy Bis (acetinoleate acetate) titanium; di_i_propoxy.bis (acetylacetone) titanium.

As the sulfur-containing compound, a nonmetallic sulfide or an organic sulfur compound having an SH group can be used. The nonmetal sulfide is preferably a compound of sulfur and a nonmetal element that is more positive than sulfur. For example, hydrogen sulfide (HS) or carbon disulfide (CS)

2 2 Power S In particular, it is preferable to use hydrogen sulfide having good reactivity. As the organic sulfur compound having an SH group, thiols (R-SH: R is an organic group such as an alkyl group; the same applies hereinafter) and dithiocarboxylic acids (R-CSSH) are preferably used. These organic sulfur compounds may have a functional group other than SH, for example, an amino group.

[0042] The solvent is an aprotic solvent that is not a protic solvent such as ethanol or methanol. It is preferable to use a solvent. For example, it is preferable to use acetonitrile-dimethylformamide, and particularly preferable to use acetonitrile. This is because H + of hydrogen sulfide easily attaches to the solvent molecules, and HS— having high reactivity with metal organic compounds (eg, tetraisopropoxytitanium) can be efficiently produced. The solvent is not limited to one type, and a mixture of a plurality of solvents may be used. For example, a mixture of a non-polar solvent such as benzene and acetonitrile can be used.

[0043] Further, in order to exhibit photocatalytic activity, it is necessary to crystallize the metal oxide, and it is preferable to calcine the precursor in a temperature range of at least 300 ° C. On the other hand, when the temperature becomes high, sulfur is easily released from the metal oxide. Therefore, the firing is preferably performed at a temperature of 700 ° C. or less. The precursor may be fired in an atmosphere containing oxygen, for example, by heating in dry air or humid air. Water (H 2 O) remains organic matter in humid air

2

The metal oxide crystallizes at a lower temperature than in the dry air to promote the removal of the metal oxide. From the above, it is preferable to fire in a temperature range of 450 ° C to 550 ° C in dry air, and it is preferable to fire in a temperature range of 350 ° C to 500 ° C in wet air. Masuri,

Further, a mixed gas generated by passing a titanium compound, a tin oxide or a zinc oxide through a solvent in which a sulfur compound is dissolved using a nitrogen gas as a carrier gas is supplied, and the temperature is raised from room temperature to a predetermined processing temperature. By performing the above, a metal oxide can also be obtained. At this time, carbon disulfide (CS) or hydrogen sulfide (HS) can be used as the sulfur compound. Ma

twenty two

Further, it is preferable that the predetermined reaching processing temperature is set to 400 ° C. or lower. In particular, it is preferable that the temperature be 100 ° C or more and 300 ° C or less.

Another example of the synthesis of nitrogen-containing titanium oxide is a method in which urea and titanium tetraisopropoxide are mixed in ethanol, and then the dried precursor is calcined in an oxidizing atmosphere at a temperature in the range of 400 to 700 ° C. . The processing temperature is more preferably in the range of 450 to 600 ° C. In addition, thiourea or thiourea dioxide may be used instead of urea, and various alcohols such as isopropyl alcohol may be used as the solvent.

[0046] By subjecting titanium carbide to heat treatment in an oxidizing atmosphere, carbon-containing titanium oxide can be obtained. The heat treatment temperature at this time ranges from 300 ° C to 700 ° C Is preferred. Furthermore, the range of 450 ° C to 600 ° C is more preferable. In addition, titanium oxide, tin oxide, zinc oxide or their precursors are placed in a reaction vessel, and a carbon-containing gas such as methane is sealed in a state where the degree of vacuum is lower than atmospheric pressure to irradiate electromagnetic waves to irradiate carbon. Metal oxide containing can be manufactured. The pressure at this time is preferably in the range of 0.1 to 10 Torr. More preferably, the range of 0.5 to 5 Torr is preferable. If the electromagnetic wave frequency is set to, for example, 2.45 GHz, it is relatively easy to handle. If a reducing gas such as hydrogen or ammonia gas is simultaneously enclosed in the reaction vessel, the production time can be adjusted by this ratio.

[0047] By subjecting titanium oxide, tin oxide, zinc oxide or a precursor thereof to a heat treatment in an atmosphere containing a phosphorus compound gas, an oxide to which P is added can be produced.

[0048] The metal oxide produced by these methods is dissolved in a highly pure solvent such as ion-exchanged water. At this time, it is preferable to set the solid concentration to about 10% in order to obtain an appropriate viscosity. By dispersing this solution using a mechanical disperser or the like, a slurry with low sedimentation is obtained.

At this time, it is preferable that at least one of polyacrylic acid, onoresolic acid, pyrophosphoric acid, and hexametaphosphoric acid is added to the slurry as a dispersant. In addition, dispersants such as alkali salts of these acids, sodium orthosilicate and sodium metasilicate may be used.

[0050] In step S12, a solution of a predetermined metal salt is generated. Metals contained in metal salts include vanadium (V), manganese (Mn), chromium (Cr), iron (Fe), cobalt (Co), copper (Cu), yttrium (Y), zirconium (Zr), Niobium (Nb), molybdenum (Mo), and lanthanoids can be used. The same effect can be obtained by using metal salts such as nitrates, sulfates, carbonates, phosphates, acetates or chlorides of these metals. At least one of these metal salts is dissolved in a highly pure solvent such as ion-exchanged water to produce an aqueous solution. At this time, a plurality of these metal salts may be mixed and used.

In step S14, the slurry containing the metal oxide generated in step S10 and the aqueous solution of the metal salt generated in step S12 are mixed and stirred. The slurry generated in this step is a raw material of the photocatalyst in the present embodiment.

In step S16, the mixture generated in step S14 is dried and then fired. Dry Drying is preferably performed at about 100 ° C. in the atmosphere. After drying, pulverize in a mortar and then bake. The firing is preferably performed in the temperature range of 80 ° C or higher and 600 ° C or lower in the atmosphere. In particular, firing at a temperature in the range of 150 ° C to 450 ° C is preferred, and firing at a temperature in the range of 250 ° C to 350 ° C exhibits particularly high photocatalytic activity. This is because if the temperature is low, unnecessary components of the raw material remain, and if the temperature is high, nitrogen and sulfur in the base powder escape.

Further, X-ray diffraction measurement was performed on some of the obtained photocatalysts. X-ray diffraction measurement was performed using Cu-Ka radiation. From the reciprocal width / 3 (radian) and peak position 2Θ (radian) of the diffraction line measured using the Cu_Ka line (wavelength λ nm) from the diffraction line, the following Scherrer equation D = 0.94 ' ; The primary particle diameter D of the following was calculated using i Z (j3-cos θ), and as a result, the primary particle diameter D of the metal oxide was 5 nm or more and 100 nm or less. . It was found that agglomerate particles between 01 μm and 50 μm were formed.

[0054] XPS measurement was performed on these photocatalysts. The measurement was performed using PHI-5500MC (manufactured by ULVAC FAI) using Mg-α-rays. Before the measurement, no pretreatment such as etching of the sample was performed, and the measurement was performed with the surface of Sampnolet as it was. As a result, it was found that the metal compound may be added from the aqueous solution of the metal salt to the surface of the metal oxide or to the inside of about 3 nm which can be analyzed by XPS. From the chemical shift of the spectrum measured by XPS, it is considered that the metal compound is contained in a state of being bonded to an oxygen atom or in a state of a hydroxide. In particular, it is highly probable that the oxide is contained in a valence lower than the maximum valence that can be stably present as an oxide in the atmosphere. Alternatively, it is considered that the metal exists in the form of nitrate, carbonate, sulfate, phosphate, acetate or chloride.

[0055] Further, the content of the metal salt was determined to be 0.0005% by weight to 10% by weight in terms of metal when identified from the spectrum of the XPS measurement for the photocatalyst exhibiting high photocatalytic activity in the visible light region. Something was preferred. In particular, in order to obtain high photocatalytic activity under visible light irradiation, 0.001% by weight or more and 6% by weight or less are preferred 0.05% by weight or more and 3% by weight or less 0.1% by weight More than 1.5% by weight or less was most preferred. [0056] The reason why the photocatalyst obtained in this embodiment exhibits high photocatalytic activity under visible light irradiation is that the photocatalyst is supported on the surface of a metal oxide such as titanium oxide, titanium oxynitride, or titanium sulfate. Of a metal compound such as CuO or FeO that has been deposited or doped inside the vicinity of the surface of the metal oxide.

2

This is considered to promote the charge separation of generated electrons or holes. It is also considered to extend the life of electrons or holes excited by light irradiation.

Hereinafter, examples of the present invention along the above-described embodiments and comparative examples corresponding to the examples will be described. However, these examples show only a part of the present embodiment, and the present embodiment is not limited to the scope of these examples.

(Comparative Example 1)

As Comparative Example 1 for the present invention, an ultraviolet-responsive titanium oxide photocatalyst (model number PC500) manufactured by Millennium Chemical Co., Ltd. was prepared. In Comparative Example 1, no particular treatment was performed.

(Comparative Example 2)

250 g of titanium oxide (ST01, manufactured by Ishihara Sangyo Co., Ltd.) was placed in a quartz container, and heated at 600 ° C. for 180 minutes while flowing ammonia gas through the container at a flow rate of 100 sccm. As a result, visible light responsive titanium oxynitride exhibiting yellow color was produced. 10 g of this titanium oxynitride powder was mixed with 90 g of ion-exchanged water to produce a slurry having a solid concentration of 10%. In addition, the sedimentation was low and the slurry was made using a mechanical disperser.

[0060] After drying this slurry under a heating atmosphere of 100 ° C, the slurry ground in a mortar was fired at 300 ° C for 1 hour in the air. After calcination, the powder was crushed again to obtain a photocatalyst powder.

(Comparative Example 3)

[0062] The slurry was mixed with 15.5 g of 10% nitric acid and stirred for 1 hour. Afterwards, slurry at 100 ° C After being dried in a heating atmosphere, the mixture was ground in a mortar and fired at 300 ° C. for 1 hour in the air. After firing, the powder was again ground to obtain a photocatalyst powder.

(Comparative Example 4)

A solution was prepared by mixing and dissolving acetonitrile and tetraisopropoxy titanium at a molar ratio of 20/1. Hydrogen sulfide (HS) gas is supplied to this solution at room temperature for publishing.

2

Was done. After the solution turned black, publishing was continued for another 3 hours, and the supply of hydrogen sulfide gas was stopped. Thereafter, the solution was filtered under reduced pressure to obtain a black precipitate.

[0064] Further, the precipitate was redispersed in ethanol and then filtered. After repeating redispersion in ethanol and filtration three times, the resultant was washed and air-dried to obtain a precursor powder. This precursor powder was heat-treated at 400 ° C for 6 hours in humid air.

(Comparative Example 5)

Titanium oxide (manufactured by Ishihara Sangyo Co., Ltd .: STOl OOg and 125 g of urea (Wako Pure Chemical Industries) were placed in a quartz container and heated at 450 ° C for 1 hour, then washed with sulfuric acid, further washed with ion-exchanged water and dried As a result, visible light responsive titanium oxynitride exhibiting yellow color was produced.

[0066] Titanium oxynitride powder (12 g) was mixed with 80 cc of isopropyl alcohol, and an acrylic silicon-based emulsion (manufactured by Daicel Chemical) was added as a binder agent. At this time, adjustment was made so that the ratio of titanium oxynitride / acrylic silicon emulsion was 8/2 as the solid content. Then, wet pulverization was performed using a mechanical disperser, and the mixture was diluted with isopropyl alcohol to a solid concentration of 4% to produce a photocatalyst coating liquid. This coating solution was applied to a 40 mm × 40 mm glass substrate surface using a spin coater, and dried at 110 ° C. for 3 minutes.

(Comparative Example 6)

500 g of titanium tetrachloride was added to pure water of ice water (2 liters in terms of water) and stirred to obtain an aqueous solution of titanium tetrachloride. While stirring 200 g of this aqueous solution with a stirrer, quickly add about 50 ml of aqueous ammonia (containing 13% by weight of NH) as a nitrogen source.

Three

Added. The amount of ammonia water added was adjusted so that the pH of the aqueous solution finally became about 8. After stirring the white slurry for 15 minutes, it was filtered using a suction filter. Obtained by filtration The precipitate 20m liters of ammonia water (NH 6 wt ^_0/0 containing) were dispersed in a star

Three

After stirring for about 20 hours with a filter, suction filtration was performed again to obtain a white hydrolyzate. The obtained hydrolyzate was placed in a crucible, placed in an electric furnace using an electric furnace, and heated at 400 ° C. for 1 hour to obtain a powder.

[0068] This was measured by X-ray diffraction. X-ray diffraction peaks revealed that the photocatalyst contained anatase-type titanium oxide. Furthermore, the primary particle diameter of the photocatalyst was about 13.5 nm when calculated using the half-width power of anatase (101) and the Scherrer equation of the X-ray diffraction line.

Further, the obtained powder was dried, 10 g of the powder was mixed with 90 cc of ion-exchanged water, and wet pulverization was performed using a mechanical disperser to produce a low sedimentable slurry.

[0070] On the other hand, copper nitrate hydrate (Cu (N〇) · 3Η〇) is dissolved in ion-exchanged water to obtain a copper concentration of 5%.

3 2 2

An aqueous solution was formed. This aqueous solution lg was added to the powder slurry and stirred for 1 hour. The slurry was dried at 100 ° C, crushed in a mortar, and baked at 300 ° C for 1 hour in air. Furthermore, the powder of the photocatalyst was obtained by grinding in a mortar.

(Comparative Example 7)

A slurry having a solid content of 10% was prepared by mixing 10 g of titanium oxide (ST01, manufactured by Ishihara Sangyo) and 90 g of ion-exchanged water, and was further made into a low sedimentable slurry with a mechanical disperser. Copper (II) nitrate hydrate was dissolved in ion-exchanged water to prepare an aqueous solution with a copper concentration of 5%. 100 g of the slurry and an aqueous solution of copper nitrate (lg) were mixed and stirred for one hour. At this time, the converted mixed concentration of copper was 0.5% by weight.

[0072] After drying this slurry at 100 ° C, what was ground in a mortar was fired at 300 ° C for 1 hour in the air. After calcination, the powder was crushed again to obtain a photocatalyst powder.

(Comparative Example 8)

A slurry having a solid content of 10% was prepared by mixing 10 g of titanium oxide (ST01, manufactured by Ishihara Sangyo) and 90 g of ion-exchanged water, and was further made into a low sedimentable slurry with a mechanical disperser. In addition, iron nitrate (II) hydrate was dissolved in ion-exchanged water to prepare an aqueous solution with a 5% iron concentration. 100 g of slurry and an aqueous solution of iron nitrate (lg) were mixed and stirred for one hour. At this time, the converted mixed concentration of iron was 0.5% by weight. [0074] After drying this slurry under a heating atmosphere of 100 ° C, the slurry ground in a mortar was fired in the air at 300 ° C for 1 hour. After calcination, the powder was crushed again to obtain a photocatalyst powder.

(Example 1)

Titanium oxide (manufactured by Ishihara Sangyo Co., Ltd .: STOl OOOg and 375 g of urea (Wako Pure Chemical Industries) were placed in a stainless steel container and heat-treated at 450 ° C for 120 minutes with stirring and mixing. This resulted in yellow visible light response. 10 g of this titanium oxynitride powder and 90 g of ion-exchanged water were mixed to produce a slurry having a solid content of 10./o. Low level and slurry.

On the other hand, copper (II) nitrate hydrate was dissolved in ion-exchanged water to prepare an aqueous solution of a metal salt having a copper concentration of 5%.

[0077] Thereafter, 100 g of a slurry of titanium oxynitride and an aqueous solution lg of copper nitrate were mixed and stirred for 1 hour to produce a mixed solution of a photocatalyst and a metal compound. At this time, the mixed concentration of copper was 0.5% by weight. After drying this mixed solution at 100 ° C, it was ground in a mortar and fired at 300 ° C for 1 hour in the air. Furthermore, the powder of the photocatalyst was obtained by crushing in a mortar.

[0078] The photocatalyst powder was measured by XPS without etching the outermost surface of the powder. When the composition ratio of copper in the powder was determined from the XPS measurement spectrum, the atomic ratio was 0.7 atomic%. In addition, as shown in FIG. 2, the strongest peak was observed in the region from 932 eV to 933 eV in the 2p shell spectrum. In particular, a peak was observed around 933 eV. Due to this chemical shift, copper is contained in the state of Cu〇 on the surface or inside of titanium oxynitride.

2

It is considered likely. However, it is difficult to completely identify it only from XPS measurement, and copper may be contained in the form of hydroxide or salt.

The powder of the photocatalyst was measured by X-ray diffraction. X-ray diffraction peaks revealed that the photocatalyst contained anatase-type titanium oxide. Further, the primary particle diameter of the photocatalyst was about 11.5 nm when calculated from the half width of the anatase (101) of the X-ray diffraction line using the Scherrer equation.

(Example 2) 250 g of titanium oxide (ST01, manufactured by Ishihara Sangyo Co., Ltd.) was placed in a quartz container, and heated at 600 ° C. for 180 minutes while flowing ammonia gas through the container at a flow rate of 100 sccm. As a result, visible light responsive titanium oxynitride exhibiting yellow color was produced. XPS measurement of this powder without etching showed a peak at about 396 eV derived from the N—Ti bond. 10 g of this titanium oxynitride powder was mixed with 90 g of ion-exchanged water to produce a slurry having a solid content of 10%. Furthermore, the sedimentation was low and the slurry was made using a mechanical disperser.

On the other hand, iron (III) nitrate hydrate was dissolved in ion-exchanged water to prepare an aqueous solution of a metal salt having an iron concentration of 5%.

Thereafter, 100 g of a titanium oxynitride slurry and an aqueous solution of iron nitrate lg were mixed and stirred for 1 hour to produce a mixed solution of a photocatalyst and a metal compound. At this time, the iron concentration was 0.5% by weight. After drying this mixed solution at 100 ° C, it was pulverized in a mortar and fired at 300 ° C for 1 hour in the air. Furthermore, the powder of the photocatalyst was obtained by crushing in a mortar.

[0083] The photocatalyst powder was measured by XPS without etching the outermost surface of the powder. When the composition ratio of iron in the powder was determined from the spectrum of the XPS measurement, the atomic ratio was 0.8 atomic%. In addition, as shown in Fig. 3, the strongest peak was observed in the region from 709 eV to 710 eV in the 2p shell spectrum. In particular, a peak was observed around 709 eV. From this chemical shift, it is highly probable that iron is contained in the surface or inside of titanium oxynitride in the form of Fe〇. However, it is difficult to completely identify it only from XPS measurement, and iron may be contained in the form of hydroxide or salt.

The powder of the photocatalyst was measured by X-ray diffraction. X-ray diffraction peaks revealed that the photocatalyst contained anatase-type titanium oxide. Further, the primary particle diameter of the photocatalyst was about 19. Onm when calculated from the half width of the anatase (101) of the X-ray diffraction line using the Scherrer equation.

(Example 3)

2

Was done. After the solution turns black, continue publishing for another 3 hours to supply hydrogen sulfide gas. I stopped paying. Thereafter, the solution was filtered under reduced pressure to obtain a black precipitate.

[0086] Further, the precipitate was redispersed in ethanol, and then filtered. After repeating redispersion in ethanol and filtration three times, the resultant was washed and air-dried to obtain a precursor powder. This precursor powder was heat-treated at 400 ° C for 6 hours in humid air. Thus, an anatase type titanium oxynitride powder was obtained. When XPS measurement was performed on this powder without etching, a peak derived from the S-Ti bond was observed at around 160 eV. Subsequently, 12 g of the obtained powder of titanium oxynitride was mixed with 80 cc of ion-exchanged water to form a slurry.

[0087] On the other hand, 17.2 g of copper nitrate hydrate (Cu (N〇) · 3Η0) was dissolved in 82.8 g of ion-exchanged water.

3 2 2

An aqueous solution was formed. 1.33 g of this aqueous solution was added to a slurry of titanium oxynitride. Next, wet pulverization was performed using a mechanical disperser. The slurry was dried at 100 ° C., pulverized in a mortar, and fired at 300 ° C. for 1 hour in the atmosphere. Furthermore, the powder of the photocatalyst was obtained by grinding in a mortar.

[0088] The photocatalytic properties of the photocatalysts obtained in the above Comparative Examples and Examples under irradiation with visible light were measured. Photocatalytic properties were measured as follows.

[0089] After 0.1 g of the prepared powder was placed in a glass container (100000 cc), the inside air was replaced with dry air. Thereafter, the black light was irradiated for 14 hours in advance with an ultraviolet intensity of 5. OmW / cm ² (using a light intensity meter made by Topcon, UVR-2 and UD-36). Thereafter, acetoaldehyde gas was injected into each glass container in an equimolar amount. Specifically, the amount of gas equivalent to 1 OOOppm in the container (100000cc) was injected with a microsyringe. After that, the gas was adsorbed on the surface of the powder by leaving it at a place for 12 hours. Visible light with a wavelength of 410 nm or more is radiated from a 10-W fluorescent tube (Matsushita Electric Works, FL10N) equipped with an ultraviolet cut filter (Fuji Film, SC42) around it to measure the time-dependent changes in the concentrations of carbon dioxide and acetoaldehyde inside. Measured. The results were as shown in FIGS.

[0090] The concentration at the beginning of measurement (time 0) is the concentration after in-place adsorption, and indicates the difference in the adsorbability of each powder. In Examples 1 and 2 of the present invention, the rate of decrease in the concentration of the acetyl aldehyde gas upon irradiation with visible light was significantly improved to more than three times that of Comparative Examples 1, 2, and 6, and acetoaldehyde equivalent to 10 OO ppmm was obtained. Can be reduced to Oppm by visible light irradiation within 2 hours. Further, in the present embodiment, carbon dioxide (CO 2), The production speed has more than doubled.

[0091] Further, as can be seen from the results of Comparative Example 6 in Fig. 4, when copper oxide was supported on titanium oxide produced by a wet method such as starting from titanium tetrachloride, the photocatalyst was rather exposed. Media activity was impaired. In other words, as in Comparative Example 6, a wet-process nitrogen-containing titanium oxide prepared by preliminarily adding nitrogen to a precursor by a hydrolysis method, and a copper oxide supported on the base was used for reaction under visible light. Speed decreased.

[0092] On the other hand, in Examples 1 and 2 in which nitrogen was contained from the outermost surface side by a thermal reaction, the reaction rate at which the improvement effect was further improved was more than doubled. From the above, it can be inferred that the present invention provides higher oxides, hydroxides, and the like when the carrier has a form in which nitrogen, sulfur, or the like is present on the surface of titanium oxide in the state of containing titanium element. It is thought that the effect of supporting the salt can be obtained. The same applies to tin oxide and zinc oxide. All of the photocatalysts obtained in the above Examples had a higher reduction rate of acetoaldehyde and a higher generation rate of carbon dioxide than the photocatalyst obtained in the Comparative Example. In particular, the production rate of carbon dioxide, which is the final decomposition product, was more than twice that of the comparative example. This indicates that a photocatalyst having high photocatalytic activity under visible light irradiation can be obtained by the treatment in the examples.

[0093] Table 1 shows the results of measuring the decomposition rate of visible light by injecting an acetoaldehyde gas equivalent to 500 ppm. In Examples 1 and 2, the production rate of carbon dioxide is more than doubled as compared with Comparative Examples 2 and 3. Also in Example 3, the generation rate of carbon dioxide is more than doubled as compared with Comparative Example 4. On the other hand, in Comparative Example 6, which was a visible light photocatalyst produced by the conventional wet method, the reaction rate before the inclusion of the Cu compound was 51 ppmZh. No effect was observed. Further, in Comparative Examples 7 and 8, it was found that even if the titanium oxide having no visible light response contained a Cu or Fe compound by the method of the present invention, there was almost no difference in the catalytic performance under visible light irradiation. .

[0094] [Table 1] Light speed under visible light

[0095] On the other hand, Table 2 shows the results of measuring the time-dependent changes in the concentrations of carbon dioxide and acetoaldehyde in the container using a black light (BLB-A, manufactured by Toshiba) instead of the visible light source. At this time, the light intensity in the ultraviolet light region was set to 5. OmW / cm ² , which was about five times the light intensity in the visible light region.

[Table 2] Photocatalytic reaction rate under ultraviolet light irradiation

[0097] Each of the photocatalysts obtained in the above examples exhibited almost the same reduction rate of acetaldehyde and the generation rate of carbon dioxide as the photocatalyst obtained in the comparative example. That is, in the processing in the embodiment, the effect of improving the photocatalytic activity in the ultraviolet light region is small. It can be said that the process is effective in improving the photocatalytic activity in the visible light region. In Comparative Examples 7 and 8, even if Cu and Fe were added to titanium oxide by the method of the present invention, no effect of improving the reaction speed with ultraviolet light was observed. [0098] In the same manner as in Examples 1 and 2, sampnoles in which the contents of the Fe compound and the Cu compound were respectively changed were separately produced. Table 3 shows the results of measuring the carbon dioxide generation rate for these samples. As is evident from Table 3, the content of Fe and Cu compounds is effective within the range shown in Table 3, but the photocatalytic activity under visible light is most improved especially at around 0.5% by weight. I do.

[0099] Table 4 shows the post-heat treatment temperature and the carbon dioxide gas reaction rate when Cu and Fe were contained in a weight ratio of 0.5%. Without heat treatment, Cu and Fe are not converted to oxides, but are considered to be fixed to the surface in the form of metal, hydroxide, or salt. At this time, the carbon dioxide generation rates are all low. In contrast, heat treatment increases the reaction rate. The reaction rate at 100 ° C is higher than that of Comparative Examples 2 and 3, and the highest in the temperature range of 250 ° C to 350 ° C. In the 300 ° C treatment, Cu and Fe are mainly lower than Cu Fe and FeO, respectively, as the result of XPS mentioned above.

2

It is considered to be an oxide. If the treatment is performed at a higher temperature to further promote the oxidation of the Cu and Fe compounds, the reaction rate will decrease. However, at a temperature of 600 ° C. or lower, the reaction rate is higher than that of Comparative Examples 2 and 3. The large decrease in the reaction rate in the treatment at 700 ° C is considered to be due to the decrease in visible light responsiveness due to the escape of nitrogen added to titanium oxide. That is, the effect of the present invention can be obtained by performing heat treatment in the range of about 100 ° C. to 600 ° C.

[0100] [Table 3]

[0101] [Table 4] (Photocatalytic reaction rate under visible light irradiation twice)

(Example 4)

100 g of titanium oxide (manufactured by Millennium Chemical Co., Ltd .: PC500) and 125 g of urea (Wako Pure Chemical Industries, Ltd.) were placed in a stone container and heated at 450 ° C. for 60 minutes. Next, it was washed with sulfuric acid, further washed with ion exchange water, and then dried. As a result, visible light responsive titanium oxynitride exhibiting yellow color was produced. 12 g of this titanium oxynitride powder and 80 cc of isopropyl alcohol were mixed.

[0103] On the other hand, 17.2 g of copper nitrate hydrate (Cu (NO) 3Η0) was dissolved in 82.8 g of ion-exchanged water.

3 2 2

An aqueous solution was formed. 1.33 g of this aqueous solution was added to a solution of titanium oxynitride and isopropyl alcohol. At this time, an acrylic silicone emulsion (manufactured by Daicel Kagaku: TT-105) was added as a binder agent. Acrylic silicon emulsion was added so that the ratio of titanium oxynitride / acryl silicon emulsion was 8/2 as solid content.

Subsequently, wet pulverization was performed using a mechanical disperser. Thereafter, the mixture was diluted with isopropyl alcohol until the solid content concentration became 4%, thereby producing a photocatalyst coating liquid. This coating solution was applied to a 40 mm × 40 mm glass substrate surface using a spin coater, and dried at 110 ° C. for 3 minutes.

(Example 5)

Place 250g of titanium oxide (ST01, manufactured by Ishihara Sangyo) in a quartz container and treat it at 600 ° C for 180 minutes while flowing ammonia gas at 1 OOOsccm. Thus, a yellow visible light responsive titanium oxynitride photocatalyst is produced. 10 g of this powder and 90 g of ion-exchanged water are mixed to produce a slurry having a solid content of 10%, and the sedimentation is reduced by a mechanical disperser. Rari. Dissolve iron (III) nitrate hydrate in ion-exchanged water to make an aqueous solution with a 5% iron concentration. 100 g of the photocatalyst slurry and an aqueous solution of iron nitrate (lg) are mixed, and pulverized and mixed again with a mechanical disperser for 15 minutes. The converted concentration of iron at this time is 0.5% by weight. Acrylic silicon-based emulsion (TT-105) manufactured by Daicel Chemical Co., Ltd. was added as an indating agent to a solid content of titanium oxynitride / acrylic-silicon emulsion = 8/2. Wet pulverized. This was diluted with ion-exchanged water to a solid concentration of 4% to prepare a photocatalyst coating solution. This coating solution was applied on a 40 × 40 mm glass substrate by a spin coater, and dried at 110 ° C. for 3 minutes.

The decomposition characteristics of methylene blue of the thin film samples of Examples 4 and 5 and Comparative Example 5 under irradiation with visible light were measured.

The photobleaching of the aqueous solution of methylene blue having a concentration of 60 μM was measured under irradiation of visible light with a filter (Fuji Photo Film) that cuts ultraviolet light of 410 nm or less wound around a 1.2 W white fluorescent lamp. Table 5 shows the change in methylene blue absorbance around 650 nm after 20 minutes of light irradiation. In this example, a very high photocatalytic activity under visible light was shown as compared with the conventional example.

[0108] [Table 5]

[0109] Further, using the samples of Examples 4 and 5, the evaluation method III (light irradiation film adhesion method) of the Antibacterial Antimicrobial Product Technology Committee was conducted under an illuminance of 2000 Lx using a 15W white fluorescent lamp (manufactured by Toshiba). An antimicrobial test of MRSA (mesitillin-resistant Staphylococcus aureus) was performed. A polyethylene film was used as a control. In Examples 4 and 5, the number of bacteria was reduced to 1 / 100,000 or less after irradiation for 24 hours, while the rate of bacterial reduction was about 1Z2 for polyethylene film. Therefore, high antibacterial properties in the present invention were confirmed.

[0110] It should be noted that the binder is not limited to the examples but silicon oxide sol, silicon resin, fluororesin, isocyanates, epoxy compound which reacts with carboxy group, aziridi Alternatively, an oxazoline-based compound, a carbodiimide-based compound, a cellulose-based binder, a polysaccharide, or amorphous titanium oxide may be used.

[0111] Examples of the solvent for preparing the coating liquid include methanol, ethanol, n-propynoleanolone, i-propynoleanolone, n-butynoleanolone, and sec-butinoleanolone. Nore, t_butinoreanorenore, n-hexinoreanorenore, n_otatinoreanorenore, ethylenglycoreno, diethyleneglycoreno, triethyleneglycoreno, ethyleneglyconele monobutinoreatenore, ethyleneglycol Noremonoethenoletheneoleate acetate, diethyleneglycol monoethynoleatenoate, propylene glycolemonomethinoleatenoate, propylene monomethyl ether acetate, diacetone alcohol, benzene, toluene, xylene, tetrahydrofuran, dioxane, a Ton, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, ethyl acetate, propyl acetate, butyl acetate, propylene carbonate, methyl lactate, ethyl lactate, normal propyl lactate, isopropyl lactate, methyl 3_ethoxypropionate, Ethyl 3-ethoxypropionate or a mixture thereof with water may be used.

[0112] Solvents for producing the oxide containing nitrogen, sulfur, carbon, and phosphorus according to the present invention include methanol, ethanol, n- Propyl alcohol, i-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, t-butylinoreanolone, n-hexinoleanoreone, n-otatinoleanoleone, ethylene glycol, Diethylene glycol, triethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene monomethyl ether acetate, diacetone alcohol, benzene, toluene, xylene, tetrahydro Orchid, dioxane, acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, ethyl acetate, propyl acetate, butyl acetate, propylene carbonate, methyl lactate, ethyl lactate, normal propyl lactate, isopropyl lactate, 3_ethoxypropyl Methyl onate, ethyl 3-ethoxypropionate and the like can also be used.

[0113] The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the spirit and scope of the present invention.

Claims

The scope of the claims

[1] Vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium on or inside a metal oxide containing at least one of nitrogen, sulfur, carbon, and phosphorus

A photocatalytic medium which exhibits photocatalytic activity under visible light irradiation, in which at least one of molybdenum, molybdenum and lanthanoid is contained in a state of being bonded to an oxygen atom, in a hydroxide state or in a salt state.

[2] The photocatalyst according to claim 1,

A photocatalyst, wherein the metal oxide is at least one oxide of titanium, tin, and zinc.

[3] In the photocatalyst according to claim 1,

The photocatalyst according to claim 1, wherein the metal oxide contains at least one of nitrogen and sulfur.

[4] The photocatalyst according to claim 1,

At least one of vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum, and lanthanoids in a valence lower than the maximum valency that can be stable as an oxide in the atmosphere A photocatalyst body comprising:

[5] The photocatalyst according to claim 1, wherein

A photocatalyst comprising vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum, and a lanthanoid in a range from 0.01% by weight to 6.0% by weight.

[6] The photocatalyst according to claim 4, wherein

A photocatalyst containing at least one of iron and copper, and having a maximum peak at 709 eV to 710 eV and 932 eV to 933 eV, respectively, in a 2p shell spectrum measured by XPS.

[7] The photocatalyst according to claim 4,

A photocatalyst comprising at least one of CuO and FeO.

2

[8] The photocatalyst according to claim 4, A photocatalyst comprising at least one of iron or copper nitrates, carbonates, sulfates, phosphates, acetates and chlorides.

In the photocatalyst according to claim 4,

A photocatalyst having a primary particle diameter of 5 nm or more and 50 nm or less.

Metal oxides containing at least one of nitrogen, sulfur, carbon, and phosphorus, and at least one salt of vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum, and lanthanoids And a photocatalyst raw material comprising:

A metal oxide or a precursor thereof, an ammonium salt or aqueous ammonia, and at least one salt of vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum, and lanthanoid. Characteristic photocatalyst raw material.

Metal oxides or precursors thereof, at least one of urea, thiourea, urea dioxide and thiourea dioxide, and vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum and lanthanoids A raw material for a photocatalyst, comprising: at least one salt.

11. The photocatalyst raw material according to claim 10, wherein the metal oxide is titanium oxide.

The photocatalyst raw material according to claim 11,

The precursor of the metal oxide is at least one of titanyl sulfate, titanium sulfate, hydrous titanium oxide, titanium hydroxide, titanium alkoxide, metatitanic acid, orthotitanic acid, hydrated titanium oxide, titanium chloride, and an organic titanium compound. A photocatalyst raw material comprising:

A first step of adding at least one of nitrogen, sulfur, carbon and phosphorus to the metal oxide or its precursor;

A state in which at least one of vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum, and lanthanoid is bonded to an oxygen atom on the surface or inside of the metal oxide or the precursor, hydroxide A second step of containing in the form of a salt or a salt;

Production of a photocatalyst having photocatalytic activity under visible light irradiation, characterized by containing Construction method.

[16] At least one of vanadium, manganese, chromium, iron, cobalt, copper, yttrium, dinolecodium, niobium, molybdenum, and lanthanoid on or in the surface, in the state of hydroxide or salt A method for producing a photocatalyst having photocatalytic activity under visible light irradiation, characterized by adding at least one of nitrogen, sulfur, carbon and phosphorus to a metal oxide or a precursor thereof contained in a state. .

[17] Vanadium, manganese, chromium, iron, cobalt, copper, yttrium, dinoreconium, niobium, molybdenum on the surface or inside of a metal oxide or a precursor thereof to which at least one of nitrogen, sulfur, carbon and phosphorus is added A method for producing a photocatalyst having photocatalytic activity under visible light irradiation, wherein at least one of the lanthanoids is contained in a state of being bonded to an oxygen atom, in a state of a hydroxide or in a state of a salt.

[18] Metal oxides containing at least one of nitrogen, sulfur, carbon and phosphorus and at least one of vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum and lanthanoids A first step of mixing the two salts,

A second step of heating the mixture at a temperature not lower than 80 ° C and not higher than 600 ° C;

A method for producing a photocatalyst having photocatalytic activity under irradiation with visible light, characterized by comprising:

[19] a first step of heating the metal oxide or its precursor in an atmosphere containing ammonia gas,

Mixing a product obtained in the first step with at least one salt of vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum, and lanthanoid; Process and

A third step of heating the mixture obtained in the second step at a temperature of 80 ° C or more and 600 ° C or less,

[20] Metal oxide or its precursor and at least one of amide, imide, urea, thiourea, urea dioxide, thiourea dioxide, melamine, guanidine, cyanuric acid, biuret, and peracil A first step of heating the mixture of

A second step of mixing the product obtained in the first step with at least one salt of vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum, and a lanthanoid. ,

[21] a first step of mixing a metal oxide precursor and a nonmetal sulfide or an organic sulfur compound having an SH group,

A second step of heating the product obtained in the first step in an atmosphere containing oxygen;

A third step of mixing the product obtained in the second step with at least one salt of vanadium, manganese, chromium, iron, cobalt, copper, yttrium, zirconium, niobium, molybdenum, and a lanthanoid. ,

A fourth step of heating the mixture obtained in the third step at a temperature of not less than 80 ° C and not more than 600 ° C;

22. The method for producing a photocatalyst according to claim 15, wherein the metal oxide is titanium oxide.

[23] The method for producing a photocatalyst according to claim 15,

The precursor of the metal oxide is at least one of titanyl sulfate, titanium sulfate, hydrous titanium oxide, titanium hydroxide, titanium alkoxide, metatitanic acid, orthotitanic acid, hydrated titanium oxide, titanium chloride, and an organic titanium compound. A method for producing a photocatalyst, characterized in that:

[24] The method for producing a photocatalyst according to claim 21,

The precursor of the metal oxide includes an organic compound of a metal, a halide and an oxyhalogen. A method for producing a photocatalyst, comprising at least one oxide.