Optical and structural properties of TiO2 nanopowders with Ce/Sn doping at various calcination temperature and time

In this paper, the influence of calcination temperature and time has been investigated on the structural, morphological, optical, and photo-catalytic properties of Sn/Ce co-doped TiO 2 nano-powders prepared via sol–gel process. They were calcined at the temperatures in the range of 475–975 °C for 1 and 2 h. The photocatalytic ability of TiO 2 powders was evaluated by means of methylene blue degradation experiments conducted under the irradiation of simulated solar light. The X-ray diffraction results showed that the tensile strain in the host lattice was present. The comparison with undoped and Sn or Ce-doped TiO 2 , co-doped TiO 2 shows an obviously higher catalytic activity under visible light irradiation. The absorbance spectrum of Ce and Sn co-doped TiO 2 exhibited significant red-shift to visible region. The red-shift is caused by the appearance of a new electronic state in the middle of the TiO 2 band-gap. FESEM images show the formation of doped TiO 2 nanoparticles with small size in structure and spherical in shape. The FTIR spectra exhibited peaks corresponding to the anatase and rutile structure phases of TiO 2 .