The Photo-absorbency Effect of Size and Doping SnO2 in Nano TiO2

Quantum-sized Titania and SnO2-doped Titania were prepared by Sol-Gel method. After heat treatment at different temperatures, powder samples with different sizes (3~12 nm) were obtained. These samples were characterized with X-ray diffraction, eletron diffraction and reflect spectrum. Experiment shows that doped SnO2promotes the anatase→rutile phase transformation process, and reduced the temperature of phase transition. The doped SnO2restrain the growth of nano crystals of TiO2. Quantum-size effect of nano-Titana was observed. But shift of optical absorption edge was not so apparent when concentration of SnO2changed. Probable reasons were discussed.