Abstract: The pure TiO_2 and Mo-doped TiO_2 nanoparticles were prepared by Sol-gel method with tetrabutyl titanate as raw material and characterized by XRD, UV-VIS and XPS. The photocatalytic activity was investigated by degradation of methylene blue. Effects of calcined temperature and doping content of Mo on crystal lattice distortion, grain size, crystal phase, optical properties and photocatalytic activities were investigated. The results show that most of Mo~(6+) takes the place of Ti~(4+) in the crystal lattice of TiO_2, which leds to distortion of crystal lattice, restrains the increase of grain size and inhabits the phase transformation from anatase to rutile of TiO_2. Exciation wavelength red shift more with doping more Mo content calcined at 450 ℃. The content of anatase phase in 1.8%Mo-TiO_2 mixed crystal calcined at 600 ℃, and inducing exciation wavelength blue shift. Doping with the appropriate content of Mo improves the photocatalytic activity of TiO_2, the photocatalytic activity of 1.8%(in mole) Mo doped TiO_2 nanoparticles is optical calcined at 600 ℃.

Key words: Mo%titanium dioxide%photocatalytic degradation%methylene blue