Photocatalytic Oxidation of Carbon Monoxide over NiO/SnO_2 Nanocomposites under UV Irradiation

摘要

The NiO/SnO_2 nanocomposites have been prepared by the simple coprecipitation method and further characterized by the XRD, SEM, TEM, UV-Vis, and BET. X-ray diffraction (XRD) data analyses indicate the exclusive formation of nanosized particles with rutile-type phase (tetragonal SnO_2) for Ni contents below 10 mol%. Only above 10 mol% Ni, the formation of a second NiO-related phase has been determined. The particle size is in the range from 12 to 6nm. It decreases with increasing amounts of doping NiO. The morphology of NiO-doped SnO_2 nanocrystalline powders is spherical, and the distribution of particle size is uniform, as seen from transmission electron microscopy (TEM). The photocatalytic oxidation of CO over NiO/SnO_2 photocatalyst has been investigated under UV irradiation. Effects of NiO loading on SnO_2, photocatalyst loading, and reaction time on photocatalytic oxidation of CO have been systematically studied. Compared with pure SnO_2, the 33.3 mol% NiO/SnO_2 composite exhibited approximately twentyfold enhancement of photocatalytic oxidation of CO. Our results provide a method for pollutants removal. Due to simple preparation, high photocatalytic oxidation of CO, and low cost, the NiO/SnO_2 photocatalyst will find wide application in the coming future of photocatalytic oxidation of CO.