Photocatalytic study of TiO2 thin films deposited by DC reactive magnetron sputtering and spray pyrolysis methods

Amorphous and polycrystalline titanium dioxide thin films were deposited by DC reactive magnetron sputtering and spray pyrolysis methods on glass and glass coated with fluorine tin oxide (FTO). The films were characterized by X-ray diffraction, atomic force microscopy (AFM) and UV-visible spectroscopy. The photocatalytic activity of the samples was tested on the degradation of methylene blue. For films deposited by the sputtering technique, we have studied the effect of the total pressure of an Ar-O(2) gas mixture on phase composition, crystallinity and the photocatalytic properties. Also TiO(2) thin films have been prepared by spray pyrolysis using a low concentration of titanium precursor at different substrates temperatures. The best photocatalytic properties in respect with methylene blue degradation were obtained for TiO(2) thin films in anatase phase with an open structure. These films were prepared at high total pressure (16 mTorr) and at moderate substrate temperatures (400 degreesC) by sputtering and spray pyrolysis respectively.