Abstract: TiO₂/SnO₂ composite thin films were prepared on soda-lime glass with the sol-gel method. The influence of
SnO₂ doping concentration, heat-treatment temperature and film thickness on the super-hydrophilicity and photocatalytic activity of the composite
films was studied by XRD, XPS, UV-spectra, measuring the contact angle and the degradation of methyl orange. The results indicate that the doping of SnO₂
into TiO₂ can improve their hydrophilicity and photocatalytic activity, and the composite film with 1%-5% SnO₂ and heat-treated at
450℃ is of super-hydrophilicity. The optimal SnO₂ concentration for the photocatalytic activity is 10% and larger film thickness is helpful
to reduce the contact angle of the composite films.

Key words: TiO₂/SnO₂ composite film, sol-gel, photocatalytic activity, contact angle