Titanium dioxide thin films supported on glass containing 0.1, 0.5 and 0.8 at % of platinum-dopant were prepared by the microemulsion templating. The resulting films had an average size of TiO2 nanoparticles of 15-20 nm with a narrow size distribution and a mesoporous film structure. The thin films prepared showed a TiO2 anatase structure and shifted the UV-vis absorption to visible light region. The Pt-modified TiO2 thin films possessed the higher photocatalytic activity than that of TiO2 thin films alone for the photodegradation of the methyl orange dye in the visible light range. The mechanism of photocatalytic activity enhancement of the Pt-modified TiO2 thin films was discussed. (c) 2005 Elsevier B.V. All rights reserved.