Abstract: The uniform transparent TiO2/SiO2 composite nanometer thin films were prepared via solgel processing on the soda lime glass substrates.The photocata lytic activity of the asprepared TiO2/SiO2 composite nanometer thin films obvi ously decreases when the amount of SiO2 addition is large.However,the photocatal ytic activity has no obvious change when the amount of SiO2 addition is small (T able 2).The addition of SiO2 can suppress the grain growth of TiO2 crystal,incre ase the hydroxyl content of TiO2 film,decrease the contact angle for water of Ti O2 films and enhance the hydrophilic property of TiO2 films.The superhydrophil ic TiO2/SiO2 composite nanometer films with the contact angle of 0o were obtaine d by the addition of 10％20％ (mole fraction) SiO2.

Key words: TiO₂/SiO₂ composite nanometer thin films, Sol-gel processing, Phot ocatalytic activity, Super-hydrophilic property