表面物种修饰异相结TiO2光子晶体构筑及其可见光活性协同增强机制

项目名称： 表面物种修饰异相结TiO2光子晶体构筑及其可见光活性协同增强机制

项目编号： No.51302269

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 王恩君

作者单位： 中国科学院合肥物质科学研究院

项目金额： 25万元

中文摘要： 相比于TiO2纳米粉体，TiO2薄膜光催化剂由于易回收、可重复利用等优点，而具有重要的实际应用价值。但其致密结构导致反应接触面积小，同时纯TiO2只能被紫外光激发,因而存在太阳能利用率低、光催化活性不高等问题。本项目拟采用表面物种修饰增强TiO2可见光吸收，构筑锐钛矿/金红石异相结促进光生电子-空穴的有效分离，构建反蛋白石结构光子晶体实现慢光子增强可见光光化学过程；采用同步辐射XAFS/EXAFS结合XPS等精细表征，从原子尺度观测表面物种的局域原子结构，研究其在催化剂表面的化学形态和络合机理，深入理解其微观吸附机制；利用其他常规表征技术，结合理论模拟计算，研究表面物种对催化剂晶体结构、能带结构和表面微结构等性质的影响；测试光催化活性，揭示表面物种、异相结和慢光子效应对TiO2基催化剂光催化活性协同增强机理。该项目的开展将为发展新型高效可见光催化剂提供新的理论依据。

中文关键词： 可见光催化剂；表面修饰；异相结；光子晶体；光催化机理

英文摘要： Compare with nano powers, TiO2 thin film photocatalyst is recyclable and reusable. Therefore its practical application value is very important. However, the interface area of TiO2 thin film is low owing to its dense structure and pure TiO2 is only sensitive to UV light, which results in a low photoactivity by using solar energy. In this project, the surface species modification will be selected to improve the visible light absorption of TiO2; heterophase junction will be formed to enhance the separation of charge carriers; inverse opal photonic crystal will be built to realize amplified photochemistry with slow photons. By using the XAFS/EXAFS, we will investigate the microcosmic adsorption mechanism of surface speices on the TiO2 surface. And its effects on the crystal structure, energy band structure and surface microstructure will be studied, by using the general characterization techniques and theoretical simulation calculation. Photocatalytic decomposition of formaldehyde is used to evaluate the photocatalytic activity of the resultant catalysts. On the basis of these characterization results, we will thoroughly investigate the principles of enhanced photoactivity ascribed to the surface species, heterophase junction and slow photons. This project will facilitate the development of novel high-efficiency vis

英文关键词： visible light photocatalyst；surface modification；heterophase junction；photonic crystal；photocatalytic mechanism