Photocatalytic Deposition of Gold on Nanocrystalline TiO2 Films

Nanocrystalline TiO2 films were prepared on glass supports by the dip coating technique using colloidal solutions consisting of 45 إ TiO2 particles as a precursor in order to probe the feasibility of exploiting solid state photocatalytic reactions for efficient deposition of gold. The reduction of Au3+ ions was maintained by photoirradiation of unmodified Ti- O2 films with metal ions being attached directly to the surface of TiO2. Absorption spectrum as well as atomic force microscopy measurements revealed presence of gold grains in the nanosize regime. Conductivity of deposited gold was measured in the temperature range from 45 to 295 K.