Photoinduced hydrophilicity of TiO2/WO3 double layer films

Abstract The photoinduced hydrophilicity of TiO 2 /WO 3 double layer films fabricated by conventional RF magnetron sputtering was evaluated. The photoinduced hydrophilic reaction at the TiO 2 surface during irradiation by a 10 W cylindrical fluorescent light bulb was enhanced by the presence of WO 3 under the TiO 2 layer. However, when the TiO 2 and WO 3 layers were separated by an insulating layer, the surface did not become highly hydrophilic under the same light conditions. The enhanced photoinduced hydrophilic reaction can be explained by charge transfer between the TiO 2 and WO 3 layers. TiO 2 /WO 3 double layer films may be applied as coatings on indoor products requiring antifogging and self-cleaning properties because the films produce a highly hydrophilic surface even with indoor lights.