Correlation of photoconductivity and photocatalytic activity of F-doped TiO2 coatings

The F-doped TiO2 coatings were deposited in sol-gel method on substrate of q uartz glass. The impacts of the deposition conditions, such as the content of fluo rine, sintering temperature and time, and thickness, on the phase structures and pr operties of the coatings were experimentally investigated. The spin-coated TiO2 thin films were characterized with X-ray diffraction, and its photo-catalytic activity was evaluated by degradation of methylene blue solution. The results sh ow that the photoconductivity of the F-doped TiO2 coatings significantly corr elates with its catalytic activity. A higher photoconductivity associates with a stronger photo-catalytic activity. When it comes to optimal photoconductivity and photo-catalytic activity, the F-doped TiO2 coatings can be synthesized with F-content of 2%, thickness of 331.5 nm, larger grains, and mixed rutile and ana tase phases. We suggest that the photo-catalysis of the F-doped TiO2 coatings may be characterized via physical route.