摘要
用透射式电子显微镜选区电子衍射法,直接观测粉末状TiO_2光催化剂的暴露晶面结构。从原子水平解释了锐钛矿型和金红石型,TiO_2的这两种同素异构体的光催化活性不同的原因,实验证明,锐钛矿型比金红石型光催化活性较高,其原因是前者的暴露晶面应是高的台阶密度、并且其基面结构与反应物匹配对应,作者认为,作为研究工具,SAD有较LEED的延伸和补充。
Almost.a1 solidery catalysts are in powdery state, but the theo ries on surface structure of beterogeneous catalysis are mainly from the re-sults of observation of bulky single crystal. For example, determination of the surface structure by low encrgy electron diffraction (LEED) requires single crystal surfaces only.In this paper, powdery TiO2 photocatalysts were examin ed directly by selected area diffraction (SAD) technique in a transmissior electron microscope. It was concluded that two fectors, namely the density of steps and the geometrical symmetry of surface structure, are both playing important roles in photocatalysis. The experiment attempted to establish ; way in which the powdery catalyst can be studied directly in atomic scale.
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
1989年第1期53-57,共5页
Journal of Xiamen University：Natural Science
关键词
选区电子衍射
暴露晶面结构
Powdery TiO2, Selected area diffraction, Exposed crystal sur face
