Synthesis of TiO2 photocatalyst thin film by solvothermal method with a small amount of water and its photocatalytic performance

Colloidal solutions containing nano-sized TiO2 particles were successfully obtained by adding a small amount of water and employing solvothermal metho d. A thin film obtained from this colloidal solution (Cat. 2) exhibited muc h better properties than another film obtained via a sol-gel method (Cat. 1 ). The former had smaller and more uniform TiO2 particles than the latter; it also had the anatase structure even after drying at 200 degreesC; a much thinner film of Cat. 2 could be obtained and this film could remain stably attached on a silicon wafer or on a pyrex plate after a thermal treatment. Cat. 2 coated on a gamma -alumina exhibited excellent performance for phot ocatalytic decomposition of CHCl3 under UV-light with O-2 bubbling (90% con version in 10 min), when comparing with a result obtained without the catal yst (70% conversion after 1 h). (C) 2001 Elsevier Science B.V. All rights r eserved.