TiO2多孔薄膜电极的制备、微结构及光电化学性能研究

近年来,半导体纳晶多孔薄膜作为一类重要的纳米结构材料,其光电化学性质及功能特性的研究受到人们广泛关注。由于量子尺寸效应及介电限域效应,它们的光物理、光电化学性质以及电荷传输机理明显异于多晶及单晶体材料。通过简便快捷的涂敷、浸涂或溅射等方法,半导体纳晶多孔薄膜可以在导电衬底上形成。这些薄膜具有高度多孔性、大比表面,易于用有机功能分子或半导体超微粒进行表面修饰^1-2],在太阳能转换^2]、光电子器件或电子变色器件^3]及光催化治理环境污染^4]等方面具有潜在的应用前景。因此,在光电化学、半导体物理及材料科学领域里研究十分活跃。本文采用涂敷及浸涂提拉方法制备了四种具有不同多孔率及比表面的TiO₂薄膜电极,并对其晶型、表面形貌微结构及光电化学性能进行了研究。

PREPARATION,MICROSTRUCTURE, AND PHOTO-ELECTROCHEMICAL PROPERTIES OF POROUS TiO2 THIN FILM ELECTRODES

Four kinds of different porous TiO₂ thin film electrodes were prepared by spreading and dip-coating methods. Surface morphology and microstructure were characterized by the SEM observations and structural parameters (porosity and surface roughness) determinations. Photocurrent action spectra with front and back side illuminations were used to study the photocurrent behaviours. The results indicate that the spreading TiO₂ thin film electrodes possess porous structure and different photocurrent behaviours compared with that of dip-coating TiO₂ thin film electrodes. The photoelectrochemical properties of spreading TiO₂ thin film electrodes can be improved by optimizing the film thickness and sintering temperature.