TiO2光催化机理的多时间尺度研究

项目名称： TiO2光催化机理的多时间尺度研究

项目编号： No.21203185

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： 王秀丽

作者单位： 中国科学院大连化学物理研究所

项目金额： 25万元

中文摘要： 光催化是解决环境和能源两大问题的重要途径。从超快动力学上研究光催化机理对于认识光催化过程、促进光催化科学发展具有重要意义。本人在弱激发条件下研究纯相锐钛矿和金红石TiO2，发现不同于强激光激发条件的TiO2载流子动力学过程，提出了束缚态可参与锐钛矿TiO2光催化过程，促进了真实条件下光催化机理的认识。本项目拟从动力学上，在多时间尺度对TiO2光催化剂的光催化机理进行研究，特别研究锐钛矿/金红石异相结、晶体形貌在光催化过程中的作用。通过不同时间分辨率(fs、ns、ms)的时间分辨光谱技术（发光、红外和紫外可见吸收）相结合，在多时间尺度上研究载流子动力学，揭示异相结、晶体形貌在光催化载流子动力学中的作用，确定光催化决定性步骤，促进光催化机理的全面认识。希望通过本研究，从本质上认识异相结、晶体形貌对光催化性能的促进机制，在多时间尺度上理解光催化机理，指导新型高效光催化剂的设计合成。

中文关键词： 光催化机理；表面异相结；时间分辨光谱；TiO2；Ga2O3

英文摘要： Photocatalysis has proven to be a potential solution for the environmental pollution and energy crisis problems. The research on photogenerated carrier dynamics is very important in order to fullly understand the photocatalytic process. We studied the carrier dynamics of pure phase anatase and rutile TiO2 through steady-state and time-resolved photoluminescence spectroscopy under weak excitation condition. The roles of trapped carriers in photcatalytic processes were discussed. The trapped carriers in anatase TiO2 may paly an important role in photocatalysis, while the trapped electrons may be hard to participate in the photocatalysis processes.This work is very useful for understanding the photocatalytic mechanism in actual reactions. In this research project, the photocatalytic mechanism of TiO2, especially the roles of anatase/rutile TiO2 junction and the crystal morphology, will be investigated with time-resolved spectroscopy at multiple time scales.The time-resolved spectroscopy with different time resolutions from fs to ms will be used to study the charge carrier dynamics, and to identify the key process in photocatalysis. In combination with in situ spectroscopy, the photocatalytic reaction processes will be investigated. This project will help understand the photocatalytic mechanism,and will help design

英文关键词： Photocatalytic mechanism；surface phase junction；time-resolved spectroscopy；TiO2；Ga2O3