Nano-scaled photocatalytic TiO2 thin films prepared by magnetron sputtering

Reactive r.f. magnetron sputtering was used as a PVD method for the deposition of photocatalytic TiO2 transparent films on glass substrate. X-ray diffraction, scanning electron microscopy and the measurement of the photocatalytic activity by the decomposition of methylene blue were applied for the film characterisation. The TiO2 films with the anatase structure and a variable film thickness ranging from 70 to 950 m were deposited on stationary substrate at two values of the total pressure with a goal to investigate their photocatalytic activity. It was found that the photocatalytic activity increases with increasing film thickness only if the films are prepared at higher sputtering pressures. Furthermore, 65 nm thick TiO2 films were deposited on rotating substrate and the relationship between the deposition parameters, such as the substrate temperature and the total pressure, the structure and the photocatalytic activity was studied. These thin films showed a very good photocatalytic activity when an appropriate substrate temperature (>100 deg. C) and/or total pressure (>1 Pa) are selected