Preparation and super-hydrophilic properties of TiO2/SnO2 composite thin films

Abstract SnO 2 –TiO 2 composite thin films were fabricated on soda-lime glass with sol–gel technology. By measuring the contact angle of the film surface and the degradation of methyl orange, we studied the influence of SnO 2 doping concentration, heat-treatment temperature and film thickness on the super-hydrophilicity and photocatalytic activity of the composite films. The results indicate that the doping of SnO 2 into TiO 2 can improve their hydrophilicity and photocatalytic activity, and the composite film with 1–5 mol% SnO 2 and heat-treated at 450°C is of super-hydrophilicity. The optimal SnO 2 concentration for the photocatalytic activity is 10 mol% and larger film thickness is helpful to reduce the contact angle of the composite films.