Photocatalytic TiO2 films deposited by rf magnetron sputtering at different oxygen partial pressure

Titanium dioxide (TiO2) films were deposited onto non-alkali glass substrates by r.f. magnetron sputtering at an [O2/(Ar + O2)] flow-rate of 0, 20, 40, 60 and 70%, respectively. The sputtering pressure was 10 mtorr, substrate temperature was around 450 °C after 3 h deposition. The crystalline structure, surface morphology and photocatalytic activity of the TiO2 films were affected by various [O2/(O2 + Ar)] flow-rate ratios. The films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and UV–vis–NIR spectroscopy. X-ray diffraction spectra showed that all the films display anatase (1 0 1) preferred orientation. Photoinduced decomposition of methylene blue (MB) and photoinduced hydrophilicity were enhanced when the [O2/(Ar + O2)] flow-rate increased to 60%.