Photocatalyst, process for producing the same and multifunctional members

• US 6,306,796 B1
• Filed: 07/15/1999
• Issued: 10/23/2001
• Est. Priority Date: 04/01/1997
• Status: Expired due to Fees

• Current Assignee: Otsuka Kagaku Kabushiki Kaisha
• Original Assignee: Otsuka Kagaku Kabushiki Kaisha
• Inventors: Torii, Katsura, Aki, Minoru, Suzue, Masayoshi
• Primary Examiner(s): Bell, Mark L.
• Assistant Examiner(s): Hailey, Patricia L.
• Application Number:
  US09/341,143
• Time in Patent Office: 831 Days
• Field of Search: 502/350, 423/610, 106/436, 501/134
• US Class Current: 502/350
• 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

Abstract

A titanium dioxide photocatalyst having a monoclinic crystal structure is prepared by subjecting a titanium dioxide hydrate fiber to a heat treatment at a temperature of 80 to 350° C., and then further heat treatment at a temperature of 360 to 650° C., and a multifunctional material is obtained by use of the photocatalyst.

Claims

1. A titanium dioxide photocatalyst having a monoclinic crystal structure;

wherein said photocatalyst is irradiated with light of a wave length which has energy greater than a band gap of the photocatalyst.

2. A titanium dioxide photocatalyst as defined in claim 1 wherein the lattice constant is expressed by:

a=12.163 Å

, b=3.735 Å

, c=6.513 Å

, α

=γ

=90°

, and β

=107.29°

, and the size of a single crystal is in the range of 0.005 to 0.1 μ

m.

3. A photocatalyst as defined in claim 1 which is of monoclinic crystal structure and of a titanium dioxide polycrystal.

4. A photocatalyst as defined in claim 1 wherein the specific surface area is in the range of about 1 to 500 m²/g.

5. A multifunctional material containing a photocatalyst of claim 1.

6. A multifunctional material having on a substrate surface a layer containing a photocatalyst of claim 1.