The high performance photocatalytic TiO2 films were successfully obtained by a galvanostatic anodization of metallic titanium using the optimum anodization condition, subsequent to pre-nitridation treatment. The optimized anodization parameters on the formation of high photocatalytic TiO2 film were investigated. The pre-nitridation treatment was performed by annealing metallic Ti under a nitrogen atmosphere of 0.1 MPa. The anodized TiO2 film showed the high photocatalytic activities to decompose not only gaseous acetaldehyde but also tetrachloroethylene, which revealed that the anodized TiO2 film is a possible candidate of the photocatalyst for environmental purifications comparable to the best photocatalyst of fine crystalline powder. (C) 2008 Published by Elsevier B.V.