Method for producing photocatalytic particles, and method for producing hydrogen and oxygen.

Abstract

This invention provides a technology for producing photocatalytic particles with high oxygen-generating activity. [Solution] A method for producing photocatalytic particles according to one aspect of the present invention is a method for producing photocatalytic particles comprising supporting a co-catalyst on photosemiconductor particles having a composition represented by the following general formula (I), comprising: an oxidation treatment step of oxidizing the photosemiconductor particles; and a co-catalyst supporting step of supporting the co-catalyst on the photosemiconductor particles after the oxidation treatment step, wherein the oxidation treatment step is performed by carrying out at least one of the following (i) and (ii): (i) oxidizing the photosemiconductor particles in an oxidizing agent solution; (ii) oxidizing the photosemiconductor particles by heating them in an oxidizing atmosphere at a temperature greater than 300°C and 450°C or less. M a Ti b O c S d …(I) (However, M is one or more combinations selected from Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Y, and is a number with a=1.7~2.3, b=2, c=4.7~5.3, and d=1.7~2.3.)

Claims

1. A method for producing photocatalytic particles comprising supporting a co-catalyst on photosemiconductor particles with a composition represented by the following general formula (I), An oxidation treatment step for oxidizing the aforementioned optical semiconductor particles, A co-catalyst loading step, wherein the co-catalyst is supported on the photo-semiconductor particles after the oxidation treatment step, Includes, In the oxidation treatment step, at least one of the following treatments (i) and (ii) is performed: (i) Oxidize the optical semiconductor particles in an oxidizing agent solution; (ii) The photosemiconductor particles are oxidized by heating them in an oxidizing atmosphere at a temperature between 300°C and 450°C. A method for producing photocatalytic particles. M ａ Ti ｂ O ｃ S ｄ …(I) (However, M is one or more combinations selected from Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Y, and is a number where a = 1.7 to 2.3, b = 2, c = 4.7 to 5.3, and d = 1.7 to 2.3.)

2. The process further includes at least one of the following pretreatment steps: (a) and (b): (a) Heat treatment in air in which the optical semiconductor particles are heated in air at a temperature of 100°C or higher and 300°C or lower; (b) An acid treatment step of contacting the optical semiconductor particles with at least one acid selected from sulfuric acid, nitric acid, hydrochloric acid, and aqua regia. The oxidation treatment step is performed on the photosemiconductor particles after the pretreatment step. A method for producing photocatalytic particles according to claim 1.

3. The method for producing photocatalytic particles according to claim 1, wherein the oxidizing agent solution is at least one oxidizing agent solution selected from the group consisting of transition metal compound solutions, peroxide solutions, hypochlorous acid solutions, chlorate solutions, bromate solutions, iodate solutions, and halogen gas solutions.

4. The aforementioned optical semiconductor particle is M ２ Ti ２ O ５ S ２ A method for producing photocatalytic particles according to claim 1, having the following composition.

5. The method for producing photocatalytic particles according to claim 1, wherein the photocatalytic particles are photocatalytic particles for the total decomposition of water.

6. A method for producing hydrogen and oxygen, comprising generating hydrogen and oxygen using photocatalytic particles produced by the method for producing photocatalytic particles described in any one of claims 1 to 5.

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