TiO2 films were prepared using RF magnetron sputtering with a variety of parameters such as sputtering pressure, substrate temperature, the kind of target, and atmosphere. Crystal structures and photocatalytic activities of these films under UV light irradiation were compared with sputtering conditions. In general, rutile phases were formed at low sputtering pressure and anatase phases became predominant at high pressure. Highest activities were obtained at high pressures irrespective of substrate temperatures in Ar + O atmosphere. Similar high activities were also achieved at high temperatures and high pressures when TiO2 target was sputtered in pure Ar. Although the films were produced under various conditions, it was indicated that decomposition rate of methylene blue (MB) was almost solely determined by anatase content.
