Professor Kaoru Tamada and Professor Michio Niwano at Research Institute of Electrical Communication, Tohoku University have developed Titania (Ti02) nanotube photocatalytic sheet that can highly efficiently decompose organic layer in noncontact. The research results show that ultraviolet light irradiation to Titania nanotube dispersed sheet decomposes organic layers whose surface is ten times larger than the contact area. Titania nanotube is made by anodizing Titanium metals. Two professors found that fine silver particles capped by organic molecules is helpful to evaluate noncontact photocatalyst performance for the first time in the world. This fact is expected to apply photocatalyst not only to the fields of building materials and the air purification system but also to the fields of semi-conductor photolithography process, sterilization of medical apparatuses, and water treatment equipment.

 

1. An anodization method uses electrolytic solution including perchloric acid, and makes Titania nanotube from Titanium foil as the anode. A spin coater disperses the solution including Titania nanotube. The tube’s diameter is about 100 nanometers, and length is about 1micrometer.

 

2. This study uses fine silver particles capped by organic molecules to evaluate photocatalyst performance. Fine silver particles that absorb light of a specific wavelength form uniformly assembled sheet. This novel method is helpful to evaluate noncontact photocatalyst performance.

 

3. Despite surface coverage with a Titania nanotube of around 10 %, microscopic observation found that decomposed organic layer and aggregated fine silver particles on the whole surface of the sheet after ultraviolet light irradiation for some time. The measurements have been done in the open system, not in a hermetic container, and high performance is expected in the latter.

 

4. This study uses standard Titania nanopowder on the market to compare photocatalyst performance. After evaluating the sheet made by the same method, microscopic observation found no noncontact photocatalyst performance, and decomposing seems to be limited to powder contact area. This research result shows that Titania nanotube has significantly better noncontact photocatalyst performance than Titania nanopowder.

 

5. Two professors have already asked for a patent, and presented the research results at the Japan Society of Applied Physics in March, 2009.

 

[Contact] Professor Kaoru Tamada

Research Institute of Electrical Communication, Tohoku University

Tel: +81 22-217-6100

 

[About Technology Transfer]

E-mail: tatsuki@t-technoarch.co.jp