Preparation, Characterization And Photocatalytic Activity Of Manganese Doped Tio_2 Immobilized On Silica Gel

摘要

A series of Mn-TiO_2/SiO_2 (silica gel loaded with manganese doped TiO_2) photocatalysts have been prepared by sol-gel method, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Photocatalytic activities were enhanced in photocatalytic degradation of methyl orange over Mn-TiO_2/SiO_2. XPS analysis shows that aTi-O-Si or Ti-O-Mn bond is formed on the surface of photocatalyst. Mn is doped as a mixture of Mn~(2+) and Mn~(3+) on the surface of 1.0 mol% Mn-TiO_2/SiO_2. Mn~(3+) appears to trap electrons and prohibit the electron-hole recombination. The electrons trapped in Mn~(3+) site are subsequently transferred to the adsorbed O_2. As a result, the combination of the electron-hole pair was reduced.