单粒子半导体材料光催化活性的空间分辨表面增强拉曼光谱研究

Spatial Resolved SERS Research on Single Semiconductor Photocatalyst Particle

通过块状材料溶解(BMD)方法合成了形貌规整的BiVO_4单晶样品。利用原子力显微镜联用的共焦拉曼光谱借助表面等离子增强效应从微纳尺度研究了单斜层状BiVO_4{011}和{010}晶面光催化降解行为的反应动力学过程差异,发现在{011}晶面上光催化的降解速率常数是{010}晶面的2倍。另外,光氧化探针辅助的单粒子荧光成像进一步佐证了该结果,荧光探针分子在光激发下主要在{011}晶面上被氧化。

BiVO4 single crystal was synthesized by bulk material dissociation （BMD） method. The photocataysis reaction kinetics on {011} and {010} facets were studied by spatially re- solved Surface-Enhanced Raman Spectroscopy （SERS）. It is found that the reaction rate con- stant for the photodegradation of methylene blue on {011} facets is about 2 times larger than that on {010} facet. Single-particle fluorescence microscope was used to probe the distribu- tion of photoinduced holes. The results show that the anisotropic photogenerated holes were mainly accumulated on {011} facet,which is the major reason for its fast reaction rate con- stant of photodegradation.