Abstract: Fe³⁺ion doped titanium dioxide films coated on silica(Fe³⁺-TiO₂/SiO₂) were prepared by sol-gel method. The obtained films were more effective than TiO₂nano-size powder in decomposing Rhodamine Bunder irridation with Xe lamp. In the Fe³⁺doping system, the optimum value of the Fe³⁺/Ti⁴⁺(atomic ratio ) was 0. 03 % for the photocatalytic degradation of Rhodamin B. The experimental results suggested that the photocatalytic reactions with the titanium dioxide nanosize powder and film as the catalyst proceed in two different degradation mechnisms. By the characterization using XRD, SEM, Raman, and FTIR technologies, we can conclude that the surface layer structure of TiO₂film on silica and the formation of Ti-O-Si bond play important roles with the increasing of degradation efficiency, and result in two different decomposition mechanisms for film and power.

Key words: Fe³⁺doped TiO₂/SiO₂film, Photocatalytic degradation, Reaction mechnism, Rhodamin B