芳烃光催化降解过程中TiO2失活机理及再生途径研究

项目名称： 芳烃光催化降解过程中TiO2失活机理及再生途径研究

项目编号： No.21203029

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理化学

项目作者： 张子重

作者单位： 福州大学

项目金额： 25万元

中文摘要： 光催化剂的使用寿命和可循环使用性能是光催化技术大规模实际应用无法回避的重大问题。揭示光催化剂失活的本质原因和基本规律，对解决这个问题至关重要。本项目提出构造1）表面富含羟基、2）表面富含缺陷或富电子和3）无表面羟基等三种特殊表面形态和结构的TiO2催化剂,从表面形态和结构入手来研究光催化剂失活本质的思路。研究光激发活性物种的生成规律，表征比较这些催化剂样品对芳烃光催化降解活性差异，分析产物分布随反应时间的变化规律以及反应后催化剂表面残留物种类，阐明不同表面结构和表面状态、空穴氧化和自由基氧化途径对活性稳定性的影响，确定光催化剂失活的共性与个性差异以及决定光催化剂失活的关键因素，阐明光催化剂失活的微观机制并探寻失活光催化剂的再生方法和途径，为设计高活性、高稳定性的芳烃光催化系统提供理论依据。该研究对分子层次上认识光催化剂的失活本质并指导实用高效光催化剂的设计和改性，具有重大的理论和实际意义。

中文关键词： 光催化；TiO2；失活机理；表面构筑；气相降解

英文摘要： The long-term stability and life of the photocatalyst is a key issue for its pratical application. However, the nature of deactivation and regeneration of the photocatalyst has not been really understood yet. Based on the analysis of the principle of photocatalysis, the deactivation of a photocatalyst is basically related to its electronic structure, surface defects, surface states and reaction mechanism. This project proposes a new scientific approach different from previous reports to resolve these issues. The following three types of representative surface structure of TiO2 photocatalyst are fabricated by an atomic-scale control of the TiO2 surface configuration: 1) rich in hydroxyl groups; 2) rich in defects or electrons; 3) the replacement of surface hydroxyl groups with sulfate or halide atoms for the preparation of no hydroxyl group on catalyst surface. In these controlled surfaces, a single active species is produced on each photocatalyst for the photooxidation of aromatic compounds. Thus, we can examine the relationship of photocatalytic activity and residual species on catalyst surface with single reactive oxygen species or photoinduced holes. Furthermore, the effect of surface configuration, surface group and active species on the stability and life of the photocatalyst can be clarified and found out

英文关键词： photocatalysis；TiO2；deactivation；surface-construction；gas-phase degradation