Cr-doped titanium oxide (Cr/TiO2) thin films were deposited on stainless steel and glass substrates by using the cathodic arc deposition technique. The characteristics of undoped and Cr-doped TiO2 thin films were compared by using several analytical approaches. The undoped TiO2 film as an as-deposited coating had an anatase structure, while the Cr/TiO2 film had an amorphous structure, as revealed by X-ray diffraction. After 3 h of heat treatment at 450 degrees C, the undoped and Cr-doped titanium oxide films became mixed anatase and rutile phases. The microstructure observed under a scanning electron microscope of the Cr-doped TiO2 film was more compact than that of the undoped film. UV-VIS spectroscopy indicated that chromium doping shifted the absorption edge of the titanium oxide film from the UV region to the visible region. Chromium doping extends the optical absorption range to the visible region and reduces the optical band gap of as-deposited films from 3.2 to 2.2 eV. The drop in the water contact angle from 28 degrees to zero following visible light irradiation implies that the Cr/TiO2 thin film becomes a better photocatalytic material because of better hydrophilic property. (C) 2008 Elsevier B.V. All rights reserved.