Preparation and photocatalytic properties of La-doped TiO2/ZrTiO4 heterogeneous thin films

The nano-scaled La-doped TiO2/ZrTiO4 (TLx/ZT) heterogeneous thin films were prepared by sol-gel spin-coating technique. The films were characterized by X-ray diffraction (XRD), atom force microscope (AFM) and UV-vis spectroscopy. XRD results showed that both the pure and La-doped TiO2 films were anatase phase and oriented predominantly to the (1 0 1) plane. La-doping was shown to extend the absorptivity of the heterogeneous films into the visible, which could be observed from the UV-vis spectra. The photocatalytic activity of TiO2/ZrTiO4 heterogeneous films enhanced greatly after La-doping, and reached the highest when the La dopant concentration was 0.5 mol%.