Visible Light-Responsive Photocatalyst Composition and Process for Producing the Same

• US 20080119352A1
• Filed: 01/17/2006
• Published: 05/22/2008
• Est. Priority Date: 01/18/2005
• Status: Abandoned Application

• Current Assignee: Nippon Shokubai Company Limited
• Original Assignee: Nippon Shokubai Company Limited
• Inventors: Kitaguchi, Shinya
• Application Number:
  US11/795,526
• Publication Number:
  US 20080119352A1
• Time in Patent Office: Days
• US Class Current: 502/74
• CPC Class Codes: B01D 2255/20776 Tungsten
• CPC Class Codes: B01D 2255/802 Photocatalytic
• CPC Class Codes: B01D 53/8678 Removing components of undefined structure
• CPC Class Codes: B01D 53/88 Handling or mounting catalysts
• CPC Class Codes: B01J 21/06 Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 23/30 Tungsten
• CPC Class Codes: B01J 29/89 Silicates, aluminosilicates or borosilicates of titanium, zirconium or hafnium B01J29/005 takes precedence
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 37/0215 Coating
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01G 41/02 Oxides; Hydroxides
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C03C 17/006 with materials of composite character
• CPC Class Codes: C03C 17/007 containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase
• CPC Class Codes: C03C 2217/45 Inorganic continuous phases
• CPC Class Codes: C03C 2217/475 Inorganic materials
• CPC Class Codes: C03C 2217/71 : Photocatalytic coatings

Abstract

The photocatalyst composition is a visible light-responsive photocatalyst being applicable to various applications, and exerts effect for the purification of harmful materials in the air, the decomposition and removal of dirt, anti-bacterium, and mildew resistance even under the irradiation of light mainly composed of visible light like a fluorescent lamp, and the composition is characterized in that the composition comprises the tungsten oxide that the primary particle diameter of the crystal is 10 to 100 nm and the crystal structure measured by X-ray diffraction is WO_x (2.5≦X≦3.0).

Claims

1. A visible light-responsive photocatalyst composition comprising a tungsten oxide, wherein the primary particle diameter of the crystal is 10 to 100 nm and the crystal structure measured by X-ray diffraction is WO_x (2.5≦

X≦

3.0).

2. The visible light-responsive photocatalyst composition according to claim 1, wherein the crystal structure of said tungsten oxide is WO₃ (X=3.0).

3. The visible light-responsive photocatalyst composition according to claim 1, wherein said composition further contains a titanium oxide, or a titanium oxide and an iron oxide.

4. The visible light-responsive photocatalyst composition according to claim 3, wherein 10 to 100 parts by mass of the tungsten oxide and 0.3 to 3 parts by mass of the iron oxide are contained relative to 100 parts by mass of the titanium oxide.

5. The visible light-responsive photocatalyst composition according to claim 1, wherein said composition further contains a titanium oxide photocatalyst that is excited with visible light of 380 nm or more.

6. The visible light-responsive photocatalyst composition according to claim 1, wherein the crystal structure of said tungsten oxide is WO_x (2.5≦

X≦

3.0).

7. The visible light-responsive photocatalyst composition according to claim 6, wherein the crystal structure of said tungsten oxide is one kind or more selected from the group consisting of W₂₄O₆₈ (X=2.83), W₂₀O₅₈ (X=2.90), and W₂₅O₇₃ (X=2.92).

8. The visible light-responsive photocatalyst composition according to claim 6, wherein said tungsten oxide is supported on a porous inorganic oxide.

9. The visible light-responsive photocatalyst composition according to claim 8, wherein said porous inorganic oxide is ZSM-5.

10. The visible light-responsive photocatalyst composition according to claim 6, further comprising a titanium oxide.

11. The visible light-responsive photocatalyst composition according to claim 6, further comprising a titanium oxide photocatalyst that is excited with visible light of 380 nm or more.

12. The visible light-responsive photocatalyst composition according to claim 11, wherein said titanium oxide photocatalyst that is excited with visible light of 380 nm or more is a titanium oxide supporting iron oxide.

13. A process for producing a visible light-responsive photocatalyst composition, which comprises impregnating an aqueous ammonium tungstate solution in a porous inorganic oxide and heat-treating the impregnated inorganic oxide under a reducing atmosphere.

14. The process for producing a visible light-responsive photocatalyst composition according to claim 13, wherein at least one organic carboxylic acid selected from an oxalic acid, a citric acid, a tartaric acid, a phthalic acid, a maleic acid, and a malic acid together with the aqueous ammonium tungstate solution are impregnated in the porous inorganic oxide and then heat-treated under the oxidizing atmosphere.