Development of the mapping method for surface optical constants and its application to in-situ observation of surface photoinduced reaction.

本研究从理论和实验两个方面研究了光催化薄膜表面光学常数的高分辨率光学外差显微测绘。1)光学外差显微测绘系统的基础研究为了建立基于光学外差方法的表面光学常数显微测绘，建立了基于声光调制器的探测光束扫描系统和探测光拍信号的电子学系统，并对其基本特性进行了研究。2)采用全息光栅法对薄膜TiO2光催化剂的表面过程进行了原位观察，以研究干涉UV-…下薄膜TiO2光催化剂的光诱导表面过程。更多的照明。结果表明，光催化反应中反应物和/或反应中间体的微观分布可以通过相应的表面折射率的空间调制来探讨。3)非线性电化学反应在铁电极上的时空传播研究铁电极的非线性电化学反应伴随着表面光学常数的变化而产生的非线性电化学振荡。测量了含时电位在电解液中的传播和在铁电极上的时空图样形成。在反应过程中，当恒电位器和铁电极之间串联插入电阻时，氧化物还原的时空模式以及电流振荡的脉冲形状都会发生变化。较少

The present research project was aimed, by both theoretical and experimental approaches, at the development of a high resolution optical heterodyne micromapping of the surface optical constants at the photocatalyst thin films. Those major issues studied and the results obtained are as follows :1) Basic study for the development of the optical heterodyne micromapping system.In order to establish a micromapping of the surface optical constants based on the optical heterodyne method, a scanning system of a probe laser beam using an AO modulator and the electronics detecting the optical beat signal were setupped and their fundamental characteristics were studied. The results were compared with those obtained by the holographic method described below.2) In situ observation of the surface processes at thin-film TiO2 photocatalystHolographic grating method was undertaken in order to study the photoinduced surface processes as modeled at a TiO2 thin-film photocatalyst under the interfering uv- … More illumination. It was suggested that the microscopic distribution of reactants and/or reaction intermediates upon photocatalysis can be probed in terms of the corresponding spacial modulation of the surface refractive index. Based on the experimental results those characteristic parameters for the surface processes such as kinetics and the surface mass transfer coefficient were suggested to be estimated.3) Spatiotemporal propagation of non-linear electrochemical Reaction over iron electrodeNon-linear electrochemical oscillation of iron electrode was studied in terms of the test surface reaction accompanying the change in surface optical constants. The time dependent potential propagation into an electrolyte solution and spatiotemporal pattern formation on iron electrode were measured. Concerning the reaction scheme, when the resistance was inserted in series between the potentiostat and the iron electrode, the spatiotemporal pattern of the oxide reduction varied as well as the pulse shape of the current oscillation. Less