Rutile-type TiO₂ thin films quasi-epitaxial grown by sputter deposition

Titanium dioxide (TiO₂) has been known as a photocatalyst. It is generally said the photocatalytic activity of anatase phase is superior to that of rutile phase despite the difference in the conditions of preparation for these two phases. We prepared anatase and rutile thin films under the same deposition conditions by reactive magnetron sputtering with Quasi-Epitaxial Growth (QEG) and discussed the relationship between the photocatalitic activity and the conditions of film deposition. An excellent photocatalytic performance was obtained for the rutile thin film prepared with QEG. With UV light illumination, QEG rutile exhibited a 0° contact angle with water as well as anatase and had better photo-decomposition activity than anatase. The photocatalytic activity of TiO₂ thin films is strongly affected by deposition conditions.