Photoelectrochemical Studies on the Electrode of Nano-structured TiO2 Porous Film

用光电流作用谱、光电流-电势图和瞬态光电流谱等光电化学方法研究了TiO2多孔膜电极在含不同氧化还原体系的电解质溶液中的光电转换过程.结果说明TiO2多孔股为n-型半导体，其禁带宽度为3.26eV.当在电解质溶液中加入醌二苯酸（BQ／HQ），TiO2多孔膜电极的光电流作用谱形基本与没加氧化还原对时类似。在可见光区的光电流拖尾是由于醌被光激发，然后给出电子到TiO2多孔膜导带而产生阳极光电流.而在电解质溶液中加入Fe（CN）3-6-／4-时，TiO2多孔膜电极的光电流作用谱有明显的改变.除了在小于380nm短波区有光电流峰外，还在400-600nm的可见光区观察到宽的光电流峰，大大增加了光电流转换...The photoinduced electron transfer process of the TiO2 porous film in the electrolytes containing different redox couples was investigated using photoelectrochemical techniques. The photocurrent action spectra. the potential dependence of photocurrent and the photocurrent transients indicate that the TiO2 porous film shows characteristics of semiconductor of n-type with an optical gap of 3.26eV. After adding quinhydrone (BQ/HQ) in the electrolyte, the photocurrent action spectrum is similar to that without redox couple and the photocurrent tan in the visible region is due to the injection of electron of excited state of p-benzoquinone to the conduction band of TiO2 porous film. After adding Fi(CN)(6)(3-/4-) in the electrolyte, the photocurrent, action spectrum is obviously different from that without, redox caliph,. In addition to the photocurrent peak in the region of wavelength less that 380nm a wide peak is observed in the visible region of 400-600nm which increases the efficiency at light-electric conversion, The photocurrent is anodic, at the potential more negative than 0.2V, becomes cathodic at the potential of 0.2 similar to 0.3V and is anodic again but weak at potential more positive than 0.3V. At the potential more positive than 0.2V. a cathodic spike is observed on the photocurrent transients plot at the moment of light-on, and later transforms into anodic steady state photocurrent, which can be it that the rapid injection of the photoinduced electron of the charge-transfer complex of [Fe(CN)(6)(4-)]TiO2 in the conduction band of TiO2 porous film, and then reduces Fe(CN)(6)(3-) in the electrolyte.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000207602100007&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701SCI(E)中文核心期刊要目总览(PKU)中国科学引文数据库(CSCD)211992-9981