The Visible Photocatalysis Properties of Nitrogen-doped TiO2 Thin Film

Titanium oxide films with different amounts of nitrogen doping have been deposited by the DC magnetron sputtering technique. The characteristics of the TiO2 films, such as crystal structures, chemical compositions, analyses, surface morphologies and photocatalyst effects were examined. The anatase phase of pure titanium oxide was observed to be deposited on the Al substrate at 250°C, while the mixed phase of anatase and rutile appeared as the temperature was increased to 350°C. The intensity of the anatase phase (101) was enhanced after nitrogen-doping the TiO2 films. A daylight lamp was used as the visible light source to analyze the IPA decomposition reaction on the surface of the TiO2 films. The nitrogen doped TiO2 films had good photocatalyst properties and followed the first-order kinetic model regarding decomposition of IPA. The apparent first-order rate constant of the TiO2 films with nitrogen doping was about 2.6 times larger than that of undoped TiO2 films. The results show that nitrogen doped TiO2 films can be active under visible light radiation.