In order to improve photocatalytic property of TiO2 films

the films were implanted with 40 keV V+ ions to doses of 0.6×1016

1×1016

3×1016 or 6×1016 ions/cm2. Optical band gap of the V+ ion-implanted TiO2 films were measured by a spectrophotometer. The results show that the optical band gap of TiO2 films decreased with the increasing implantion dose. Methyl orange (MO) in aqueous solution was catalyzed by the ion-implanted TiO2 films under visible light.