Abstract: TiO2 thin films were deposited on glass and quartz substrates, respectively, using the direct current reactive magnetron sputtering method. When the oxygen flow rate exceeded its threshold, the average film deposition rate was 160 nm/h and uniform and transparent TiO2 films could be obtained. The films deposited on the two substrates were all composed of anatase crystals with a preferred orientation of (220) plane, and small holes were distributed among the crystalline particles. The absorption edges of the two films were nearly at the same position in the whole spectrum although quartz had higher transmittance than the glass substrate. The titanium in the films was in the oxidation state of Ti4+, and the oxygen was in the form of O2- in TiO2 and also in H2O which was chemically and physically adsorbed on the films. The photocatalytic activity of the TiO2 films for the degradation of methyl orange was evaluated under UV irradiation. There was little difference in the photocatalytic activity between the films deposited on the two substrates although sodium and calcium ions in the glass substrate might have negative effects.

Key words: reactive magnetron sputtering, titania, thin film, glass, quartz, substrate, photocatalysis, methyl orange, degradation