Preparation of TiO2/WO3 multilayer thin film by PLD method and its catalytic response to visible light

We report about multilayer TiO2/WO3 thin films deposited on silicon and quartz glass substrate by pulsed laser deposition (PLD) method. The multilayer film has higher photocatalytic activity than TiO2 film under visible light irradiation. The films were characterized using an atomic force microscope (AFM), X-ray diffraction method (XRD) and UV–VIS absorption spectrometry. Photocatalytic efficiency of TiO2 and TiO2/WO3 multilayer thin film was also evaluated by photodecomposition of methylene blue (MB) in aqueous solution. The portion of WO3 layers in the multilayer film is very sensitive to photocatalytic property. The multilayer film containing 5% WO3 layers in thickness showed the highest dye decomposition ratio.