负载型复合半导体MoO3-TiO2/SiO2的结构与吸光性能

采用表面改性法制备了负载型复合半导体材料MoO3TiO2/SiO2,用X射线衍射、比表面测定、透射电子显微镜、红外光谱、拉曼光谱、紫外可见漫反射等技术对固体材料的结构进行了表征,并从固体材料的光响应性能和化学吸附性能方面进行了评价.结果表明,MoO3TiO2/SiO2表面存在着高度分散的MoO3和TiO2微晶,它们之间有一定的复合和键联作用,形成了Mo-O-Ti键;MoO3TiO2/SiO2复合材料表面对丙烷分子有化学吸附性能,Mo=O键上的端氧是C3H8的活性吸附位;与本体MoO3和TiO2相比,复合后MoO3TiO2/SiO2的能隙值有所增加,在紫外光区的吸光强度也明显加强,使得光生载流子的复合效率得到抑制,并产生了一定的量子尺度效应.

Surface Structure and Photon Absorption Property of Supported Coupled Semiconductors MoO3-TiO2/SiO2

Solid material of supported coupled semiconductors MoO_3-TiO_2/SiO_2 was prepared by the chemical modification method. BET, XRD, TEM,IR, Raman and UV-Vis DRS experiments were used to characterize the ~surface structure, photon absorbing and chemisorbing ability of the material. It was shown that there are some ~extremely small particles of anatase and MoO_3 crystallites dispersed well on the surface of SiO_2, which also can be coupled each other by the bonds of Ti-O-Mo. The active adsorption sites of the material exist on its surface, ~according to IR results, and C_3H_8 can be chemisorbed at the Lewis base sites of the Mo=O bonds to form molecular states. Compared with MoO_3 and TiO_2, the edge energy of MoO_3-TiO_2/SiO_2 was improved and a significant rise of the photon absorbing intensity is observed, which proves the coupled structure has stronger photon ability to take in the UV light, hold back the recombination of photoexcited electron-hole pairs and exhibit the quantum size effects.