Photocatalytic degradation characteristic of amorphous TiO2-W thin films deposited by magnetron sputtering

TiO2-W films were deposited on the slides by reactive magnetron sputtering. Properties of the films were analyzed via AFM, XRD, XPS, STS, UV-Vis and ellipse polarization apparatus. The results show that TiO2-W films are amorphous. The AFM map reveals that the surface of the film is tough and porous. The experiments of decomposing methylene blue indicate that the thickness threshold on these films is 141 nm, at which the rate of photodegradation is 90% in 2 h. And when the thickness is over 141 nm, the rate of photodegradation does not increase any more. This result is completely different from that of crystalloid TiO2 thin film.