Effect of the sintering temperature on the photocatalytic activity of ZnO+Zn2TiO4 thin films

ZnO+Zn2TiO4 thin films were obtained by the sol-gel method, the precursor solutions were prepared using two Ti/Zn ratios: 0.49 and 0.69. The films were deposited on glass slide substrates and sintered at temperatures in the 200-600 C range in increments of 50 degrees C, with the goal of studying the dependence of the photocatalytic activity (PA) on the annealing temperature. The films were characterized by X-ray diffraction and UV-Vis spectroscopy. The PA was evaluated by measuring the UV-Vis absorption spectra of the methylene blue in aqueous solution before and after photobleaching, using the Lambert Beer's principle. The higher photocatalytic activities were obtained from the films with sintering temperature around 450 degrees C, for both Ti/Zn ratios studied. (c) 2007 Elsevier B.V. All rights reserved.