Photocatalyst, process for producing the photocatalyst, and photocatalytic reaction method

• US 6,077,492 A
• Filed: 08/21/1997
• Issued: 06/20/2000
• Est. Priority Date: 01/22/1996
• Status: Expired due to Term

• Current Assignee: Petroleum Energy Center
• Original Assignee: Petroleum Energy Center
• Inventors: Fujimoto, Takanori, Kanai, Sakunobu, Yamashita, Hiromi, Sato, Kazuhito, Anpo, Masakazu
• Primary Examiner(s): Griffin, Steven P.
• Assistant Examiner(s): MEDINA SANABRIA, MARIBEL
• Application Number:
  US08/894,552
• Time in Patent Office: 1,034 Days
• Field of Search: 502/5, 502/349, 502/350, 204/157.3, 585/377, 427/523, 427/529, 427/530, 423/239.1, 315/111.81
• US Class Current: 423/239.1
• CPC Class Codes: B01D 2255/20707 Titanium
• CPC Class Codes: B01D 2255/802 Photocatalytic
• CPC Class Codes: B01D 2255/90 Physical characteristics of catalysts
• CPC Class Codes: B01D 2257/404 Nitrogen oxides other than dinitrogen oxide
• CPC Class Codes: B01D 53/8628 Processes characterised by a specific catalyst
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 35/39 Photocatalytic properties
• CPC Class Codes: B01J 37/341 making use of electric or magnetic fields, wave energy or particle radiation use of flames, plasma or lasers B01J37/349

Abstract

A titanium oxide photocatalyst having metal ions of one or more metals incorporated therein selected from the group consisting of Cr, V, Cu, Fe, Mg, Ag, Pd, Ni, Mn and Pt, wherein the metal ions are implanted from the surface to deep inside of the bulk of the photocatalyst in an amount of at least 1×10¹⁵ ions per g of the titanium oxide; a process for producing the photocatalyst; and a photocatalytic reaction method using the photocatalyst.

Claims

1. A titanium oxide phototocatalyst having metal ions of one or more metals incorporated therein selected from the group consisting of Cr, V, Cu, Fe, Mg, Ag, Pd, Ni, Mn and Pt, wherein the metals ions are implanted from the surface to deep inside of the bulk of the photocatalyst in an amount of at least 1×

10¹⁵ ions per g of the titanium oxide, wherein the metal ions are present in the titanium oxide from the surface to a depth of 1000 Å

.

2. The photocatalyst as claimed in claim 1, wherein the metal ions are of one or more metals selected from the group consisting of Cr, V, Fe, Ni and Mn.

3. The photocatalysts as claimed in claim 1, wherein the titanium oxide is selected from the group consisting of TiO₂ and SrTiO₃.

4. The photocatalyst as claimed in claim 1, wherein prior to implantation, the metal ions have a valence of one.

5. The photocatalyst as claimed in claim 1, wherein the metal ions are one or more metals selected from the group consisting of Cr, V, Cu, Mg, Ag, Pd, Ni, Mn, and Pt.

6. The photocatalyst as claimed in claim 1, wherein the metal ions are one or more metals selected from the group consisting of Cr, V, Ni, and Mn.

7. The photocatalyst as claimed in claim 1, wherein the metal ions are one or more metals selected from the group consisting of Cr and V.

8. A process for producing a photocatalyst, which comprises accelerating metal ions of one or more metals selected from the group consisting of Cr, V, Cu, Fe, Mg, Ag, Pd, Ni, Mn and Pt to an energy level of at least 30 keV and implanting the accelerated metal ions into a titanium oxide.

9. The process as claimed in claim 8, wherein the metal ions are of one or more metals selected from the group consisting of Cr, V, Fe, Ni and Mn.

10. The process as claimed in claim 8, wherein the titanium oxide is selected from the group consisting of TiO₂ and SrTiO₃.

11. The process as claimed in claim 8, wherein the metal ions are implanted into the titanium oxide catalyst from the surface to a depth of 1,000 Å

.

12. The process as claimed in claim 8, wherein the metal ions are implanted into the titanium oxide catalyst in a dose of from 1×

10¹⁴ to 1×

10¹⁹ ions/cm².

13. A photocatalytic reaction method, which comprises irradiating light in the wavelength regions from ultraviolet to visible on a titanium oxide photocatalyst having metal ions of one or more metals incorporated therein selected from the group consisting of Cr, V, Cu, Fe, Mg, Ag, Pd, Ni, Mn and Pt, wherein the metals ions are implanted from the surface to deep inside of the bulk of the photocatalyst in an amount of at least 1×

10¹⁵ ions per g of the titanium oxide, wherein the metal ions are present in the titanium oxide from the surface to a depth of 1,000 Å

.

14. The method as claimed in claim 13, wherein light in the wavelength regions from ultraviolet to visible is irradiated on the titanium oxide photocatalyst in the presence of nitrogen oxides to decompose the nitrogen oxides.

15. The method as claimed in claim 13, wherein light in the wavelength regions from ultraviolet to visible is irradiated on the titanium oxide photocatalyst in the presence of butenes to isomerize the butenes.

16. The method as claimed in claim 13, wherein the metal ions are of one or more metals selected from the group consisting of Cr, V, Fe, Ni and Mn.

17. The method as claimed in claim 13, wherein the titanium oxide is selected from the group consisting of TiO₂ and SrTiO₃.

18. The photocatalytic reaction method as claimed in claim 13, wherein prior to implantation, the metal ions have a valence of one.