权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

New decomposition method of organic environmental pollutants during photocatalytic reactions : Photocatalyst and Multi-photoexcitation

光催化反应分解有机环境污染物的新方法：光催化剂和多重光激发

基本信息

批准号：
15550013
负责人：
TOJO Sachiko
金额：
$ 2.24万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

One-electron oxidation reaction mechanisms of aromatic sulfides in a colloidal TiO_2 aqueous solution. Laser flash photolysis technique has been employed to clarify the oxidation reaction processes of 4-methylthiophenylmethanol and 2-phenythioethanol in the colloidal TiO_2 aqueous solution. The significant variations in the spectral shape and formation rates of the radical cation clearly suggest two oxidation processes with the valence band and/or trapped holes and the free OH radicals. Effects of the adsorption and the electronic interaction between aromatic compounds and the TiO_2 surface on the efficiency of the one-electron oxidation reaction. The TiO_2 photocatalytic one-electron oxidation mechanism of aromatic compounds adsorbed on the surface of a TiO_2 powder slurried in acetonitrile has been investigated by time-resolved diffuse reflectance spectroscopy. The efficiency of the one-electron oxidation of substrates adsorbed on the TiO_2 surface, which was determined from the relationship between the amount of adsorbates and the concentration of the generated radical cations, significantly depended on the electronic coupling elements, but not on the oxidation potential of substrates determined in homogeneous solution. Cascade hole transfer giving free radical cations. The formation of the 1,1-dianisylethylene (DAE) dimer radical cation during TiO_2 photocatalytic reactions was successfully investigated by the transient absorption measurement with time-resolved diffuse reflectance spectroscopy. The reaction was explained in terms of the cascade hole transfer processes from the photo-generated holes in the TiO_2 particles to free DAE in the bulk solution mediated by the radical cation of p-phenylbenzoic acid adsorbed on the TiO_2 surface.

芳香族硫化物在TiO_2胶体水溶液中的单电子氧化反应机理采用激光闪光光解技术研究了4-甲硫基苯甲醇和2-苯硫基乙醇在TiO_2胶体水溶液中的氧化反应过程。的光谱形状和自由基阳离子的形成速率的显着变化清楚地表明两个氧化过程的价带和/或捕获的空穴和自由OH自由基。芳香族化合物与TiO_2表面的吸附和电子相互作用对单电子氧化反应效率的影响。用时间分辨漫反射光谱研究了乙腈悬浮液中TiO_2光催化单电子氧化芳香族化合物的机理。吸附在TiO_2表面的底物的单电子氧化效率主要取决于电子耦合元素，而与底物在均相溶液中的氧化电位无关。级联空穴传递产生自由基阳离子。利用时间分辨漫反射光谱技术研究了TiO_2光催化反应过程中1，1-二茴香基乙烯（DAE）二聚体自由基阳离子的形成。该反应是由吸附在TiO_2表面的对苯基苯甲酸自由基阳离子介导的光生空穴向本体溶液中自由DAE的级联空穴转移过程来解释的。