Properties and morphology of CdS compounded TiO2 visible-light photocatalytic nanofilms coated on glass surface

Thin-fobidden-zone CdS compounded TiO2 films can promote the visible light photocatalytic degeneration efficiency of photocatalytic film greatly. The compounded films are prepared by sol-gel method using spinning technology on the glass surface. Additional TiO2 layer was coated on the CdS compounded TiO2 film to inhibit the solubilization of cadmium. Some pore-producing agents, such as trifluoroacetic acid and polyethylene glycol, have been doped in these additional layers. The degradation efficiency under visible light of compounded films for methyl orange is investigated by spectrophotometer. The morphology of glass surface is observed through AFM. The dissolved cadmium of films is detected by atomic absorption spectrometer. As a result, the visible light photocatalytic degradation efficiency of the compounded film is far higher than that of TiO2 film. The amount of dissolved cadmium of film surface is hardly found after the second layer was coated.