考察了Pt促进的N掺杂TiO2(Pt/N-TiO2)催化剂对光催化降解有机污染物性能的影响及其作用本质.采用X射线衍射、透射电镜、X射线光电子能谱、紫外-可见漫反射光谱、光电化学和荧光光谱等手段对催化剂进行了表征,并考察了样品在可见光下光催化降解甲基橙(MO)的反应性能.结果表明,Pt的存在并未明显改变N-TiO2的晶相和介孔结构,却增强了催化剂对可见光吸收,但这种背景吸收不利于光激发中心(N-TiO2)对可见光的吸收,从而影响Pt/N-TiO2光催化活性;高度分散在N-TiO2表面的Pt,显著地改变了催化剂表面电子结构,从而提高了N-TiO2的光催化性能.
The influence of Pt as a promoter on the photocatalytic performance of nitrogen-doped TiO2 was described.The sample was characterized by X-ray diffraction,transmission electron microscopy,X-ray photoelectron spectroscopy,UV-Vis diffuse reflectance spectroscopy,photoelectrochemistry,and photoluminescence.The degradation of methyl orange in aqueous solution under visible light irradiation was used to evaluate the photocatalytic activity of the sample.The modification of N-TiO2 with Pt did not change the crystal structure and the mesoporous structure of TiO2.The loading of Pt enhanced the material absorption in visible light region,which is assigned to background absorption that has detrimental effect on photocatalytic activity.However,the highly dispersed Pt on the surface of N-TiO2 remarkably altered the surface structure(surface state) of N-TiO2,contributing largely to the enhanced photocatalytic activity of nitrogen-doped TiO2.