Photocatalyst composition and process for its production, and photocatalyst composition-attached substrate

• US 5,780,380 A
• Filed: 12/19/1996
• Issued: 07/14/1998
• Est. Priority Date: 12/21/1995
• Status: Expired due to Fees

• Current Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Original Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Inventors: Morimoto, Takeshi, Endoh, Eiji
• Primary Examiner(s): Griffin, Walter D.
• Assistant Examiner(s): NORTON, NADINE GEORGIANNA
• Application Number:
  US08/770,731
• Time in Patent Office: 572 Days
• Field of Search: 502/305, 502/313, 502/306, 502/309, 502/353, 502/354, 502/349, 502/350, 502/340, 502/341, 502/300
• US Class Current: 502/300
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 35/39 Photocatalytic properties

Abstract

Semiconducting photocatalytic substance and fine oxide particles dispersed therein form a photocatalyst composition, with the photocatalyst composition having a band gap which is larger by at least 0.05 eV than the band gap of the semiconducting photocatalytic substance per se.

Claims

1. A photocatalyst composition comprising a semiconducting photocatalytic substance and fine oxide particles dispersed in the semiconducting photocatalytic substance, said photocatalyst composition having a band gap which is larger by at least 0.05 eV than the band gap of the semiconducting photocatalytic substance per se.

2. The photocatalyst composition according to claim 1, wherein the semiconducting photocatalytic substance is at least one member selected from the group consisting of TiO₂, Bi_2O3, In₂ O₃, WO₃, ZnO, SrTiO₃, Fe_2O3 and SnO₂.

3. The photocatalyst composition according to claim 1, wherein the fine oxide particles are at least one member selected from the group consisting of Al₂ O₃, SiO₂, SnO₂, In₂ O₃ and ZrO₂.

4. The photocatalyst composition according to claim 1, wherein the dispersed proportion of the fine oxide particles is from 20 to 80 vol % to the total of the semiconducting photocatalytic substance and the fine oxide particles.

5. A process for producing a photocatalyst composition, which comprises coating on a substrate a coating liquid for forming a photocatalyst composition, comprising a material capable of forming a semiconducting photocatalytic substance and fine oxide particles dispersed in the material, to form a thin film, and then applying heat treatment thereto to obtain a photocatalyst composition having a band gap which is larger by at least 0.05 eV than the band gap of the semiconducting photocatalytic substance per se.

6. The process for producing a photocatalyst composition according to claim 5, wherein the material capable of forming a semiconducting photocatalytic substance comprises a sol of the semiconducting photocatalytic substance or a precursor of the photocatalytic substance.

7. A photocatalyst composition-attached substrate comprising a substrate and a photocatalyst composition formed on the substrate, wherein the photocatalyst composition comprises a semiconducting photocatalytic substance and fine oxide particles dispersed in the semiconducting photocatalytic substance, and the photocatalyst composition has a band gap which is larger by at least 0.05 eV than the band gap of the semiconducting photocatalytic substance per se.

8. The photocatalyst composition-attached substrate according to claim 7, wherein the semiconducting photocatalytic substance is at least one member selected from the group consisting of TiO₂, Bi₂ O₃, In₂ O₃, WO₃, ZnO, SrTiO₃, Fe₂ O₃ and SnO₂.

9. The photocatalyst composition-attached substrate according to claim 7, wherein the fine oxide particles are at least one member selected from the group consisting of Al₂ O₃, SiO₂, SnO₂, In₂ O₃ and ZrO₂.

10. The photocatalyst composition-attached substrate according to claim 7, wherein the dispersed proportion of the fine oxide particles is from 20 to 80 vol % to the total of the semiconducting photocatalytic substance and the fine oxide particles.