Ag-doped TiO2 composite thin films prepared by sol-gel and its photocatalytic activity

Uniform, transparent anatase Ag-doped TiO2 composite thin films deposited on glass substrates have been prepared by sol-gel technology. Experimental results indicate that Ag-doped TiO, films are composed of TiO2 spherical particles 50 nm similar to 100 nm in diameter. The thickness of the TiO2 films prepared under 1 coating cycle (from dipping to heat-treatment at 500 degreesC for 1 h) is proximately 0. 09 mum. Anatase TiO2 films have (101) orientation. Studies of photocatalytic degradation show that the degradation rate constant, k, of Ag-doped TiO2 composite films is larger than that of un-doped TiO2 films. These results are explained in terms of charge separation in the Ag/TiO2 composite metal-semiconductor system.