Mechanism and behaviors of Cr~(3+)-doped TiO_2

摘要

TiO_2 powder and TiO_2 thin film on the surface of glazed ceramic tile were prepared by sol-gel method. The influences of different doping Cr~(3+) concentration on the photocatalytic activity of TiO_2 were discussed, UV-visible and X-ray diffraction analysis were used to test the performance of TiO_2 powder and film. The results indicate that photocatalytic activity of doping Cr~(3+)-TiO_2 thin film is higher than that of powder, and the interaction between Cr~(3+)-doped and substrate can greatly enhance the photocatalytic activity. The results of X-ray diffraction and pho-toabsorption show that the Cr~(3+)-doped energy level in TiO_2 is 0. 62 eV high from the top of valence band, which belongs to the type of deep energy level doping. On the basis of the semiconductor energy level theory and Cr~(3+) dopant energy level, the semiconductor energy level model of Cr~(3+) in TiO_2 powder and thin film were established, and the doping mechanisms of Cr~(3+) -doped in TiO_2 powder and thin film were analyzed.