金属-半导体催化剂的相互作用的研究—Pt/TiO2和Pt/ZnO界面结构变化对其化学行为的影响

为研究Pt-TiO_2和Pt-ZnO体系经过加温氢处理后其金属-半导体(金-半)界面性质的变化, 本工作以测量电流-电压曲线的方法检验金-半界面势垒。用动电位扫描的方法考察金-半电极在Fe(CN)_6~(4-)/Fe(CN)_6~(3-)溶液中的电化学行为。并通过Auger剖面分析证明加温氢处理可导致在金-半界面上形成一个扩散区, 说明界面扩散可能是金-半相互作用及其电学、电化学乃至催化性能发生重大变化的主要原因。

STUDIES ON METAL-SEMICONDUCTOR INTERACTION: THE EFFECT OF THE INTERFACIAL STRUCTURE ON THE ELECTROCHEMICAL BEHAVIOR OF Pt—TiO2 AND Pt-ZnO

Electric property across the Pt film-TiO_2 and Pt film-ZnO interface was characterized by the Ⅰ-Ⅴ curves. It was seen clearly that by H_2 treatment at high temperature the original rectifying property of the metal-semiconductor junction was changed into ohmic resistance contact. Electron exchange capability at the Pt film-TiO_2 and Pt-ZnO surface was measured electrochemically by making contact with a solution of Fe(CN)_6~(4-)/Fe(CN)_6~(3-). It was illustrated that the H_2 treated SMSI sample was much more feasible to charge transfer than the non-SMSI ones and it worked well either anodically or cathodically, analogous to the metallic Pt.By Auger depth profiling it was demonstrated that by heating Pt film-TiO_2 in H_2 interdiffusion at the metal-semiconductor interface happened, as a consequence the interfacial energy barrier for electron transfer was diminished and the charge transfer process greatly enhanced.