The Effects of Doping Micro Palladium on the Structure and Performance of TiO2 Powder

Abstract

The Pd-doped TiO2 powder was prepared by the sol-gel method and characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis absorption spectroscopy and X-ray diffraction. The results show that palladium exists as PdO and that the PdO crystal forms in the Pd/TiO2 powder calcined at 973 K. When the Pd/TiO2 powder is calcined at a temperature between 573K and 973 K, TiO2 mainly exists in the anatase structure, and the average diameters of the anatase TiO2 and PdO particles are less than 45 nm. The crystal lattice constant a decreases while c increases with the increasing of the calcination temperature. Compared with the pure TiO2 powder prepared under the same conditions, the phase transformation temperature from the anatase structure to the rutile structure for TiO2 in the Pd/TiO2 powder increases, the excitation wavelength of Pd/TiO2 powder is broadened to the visible light region and the visible photocatalytic activity increases obviously.