Phase selection and visible light photo-catalytic activity of Fe-doped TiO2 prepared by the hydrothermal method

Abstract It is necessary to extend the absorption range of TiO 2 based materials from the ultraviolet to the visible light region for most photo-catalytic applications of TiO 2 under solar irradiance or indoor lighting. Also, the ability to control the structural evolution, particularly the competition and transformation between different phases (anatase or rutile), is extremely important for the preparation of high efficiency TiO 2 based photo-catalysts. In this work, we have systematically studied the effects of various processing factors on the phase selection process/outcome of nanocrystalline Fe-doped TiO 2 , which includes the level of doping ions, annealing temperature, solution pH and the addition of acidic anions, using a low temperature hydrothermal method. Both Fe-doped rutile and anatase TiO 2 phases were obtained via varying the processing conditions. The visible-light photo-catalytic activity of doped materials was significantly improved over that of the pure TiO 2 nanopowders, which was demonstrated by effective degradation of methylene blue under visible light.