The Ce3+-doped and undoped nanocrystalline TiO2 films were prepared on glass substrates surface by sol-gel dip coating technique. The crystal structure and surface morphology of TiO2 films were characterized by means of X-ray diffractometer (XRD), transmission electron microscopy (TEM) and atomic force microscope (AFM). The results indicated that the Ce3+-doped TiO2 films were solely composed of the anatase phase whereas in the undoped films small amount of the rutile phase of TiO2 were present. The average crystallite size of the undoped TiO2 films was about 30nm and was decreased with Ce3+-doping in the TiO2 films. Moreover, the grains distributed more uniform and the surface roughness was smaller in the Ce3+-doped TiO2 films than in the undoped one. The action mechanism of Ce3+-doping inhibits the crystallization of the rutile phase and decreases the anatase granularity of TiO2 films is associated with its physicochemical properties, as well as ionic diffusion and valance change of Ce3+ to Ce4+ in the sintering process.
