Surface properties of doped and undoped TiO2 thin films deposited by magnetron sputtering

In this work, transparent titanium dioxide (TiO2) thin films were deposited onto microscope glass slides by means of the d.c. reactive magnetron sputtering method. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV–visible spectroscopy (UV) and contact angle analysis using the Owens–Wendt method for the surface energy calculation. The photocatalytic activity of the films was tested by measuring the photodegradation of Rhodamine-B (RhB) dye under radiation of UV light. Iron-doped TiO2 films were also prepared in order to study the Fe-doping effect on TiO2 photocatalytic activity. The influences of different iron concentrations on the contact angle of the series of Fe-doped TiO2 thin films, were investigated. The influences of total sputtering pressures on TiO2 photocatalytic activity were also investigated. It was observed that the photocatalytic activity of the TiO2 thin films was slightly improved by increasing the total sputtering pressure. Moreover, it was also observed that in general, iron-doping was detrimental for photocatalytic activity, nevertheless the films with low iron concentrations showed better photocatalytic activity than those with high iron concentrations. It was found that iron-doping has changed the wettability appetency of TiO2 coated surfaces.