Preparation of nitrogen-doped titanium oxide thin film using a PLD method as parameters of target material and nitrogen concentration ratio in nitrogen/oxygen gas mixture

Nitrogen-doped titanium oxide photocatalysts, which were reported to be activated by visible light irradiation as well as ultraviolet irradiation, have been prepared by pulsed laser deposition method using Ti, TiO, TiO₂ and TiN targets in nitrogen/oxygen gas mixture. As a result, it is found that film properties such as color, crystalline structure and atomic composition rate strongly depend on the target material and nitrogen concentration ratio in the gas mixture. It is also suggested that these films under UV light irradiation exhibit almost the same decomposition ability of methylene blue. However, the photocatalytic activity of the nitrogen-doped TiO₂ film prepared using TiN target is higher than that of the other films prepared by Ti, TiO and TiO₂ targets under normal fluorescent light irradiation.