有氧条件下可见光催化还原氯代烃体系的构建及电子转移机制

项目名称： 有氧条件下可见光催化还原氯代烃体系的构建及电子转移机制

项目编号： No.51278456

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 建筑科学

项目作者： 赵伟荣

作者单位： 浙江大学

项目金额： 80万元

中文摘要： 金属化学还原法脱除水中有毒氯代烃一直是研究的热点。针对该体系需外加电子供体及厌氧环境条件的限制，本申请类比Z-scheme可见光催化分解水产氢体系，将光催化和金属化学还原有机结合在一起，筛选和匹配具有可见光分解水产氢、产氧性能催化剂的能带结构、电子传递介质，实现水作为抑制剂捕集光生空穴；选择对氢溶解性好的金属，利用金属与半导体间的肖特基势垒，可见光还原水产生原子氢，再由金属的活性位点利用原子氢实现还原加氢脱氯反应，最终构建出一种原位供电子并不受氧影响的光催化加氢脱氯新材料和新还原体系。采用现代材料物理和化学表征手段，研究体系的结构形貌、比表面积、粒径、能带宽度、金属元素形态、光生电子寿命和密度、金属表面氢覆盖率等，探究反应体系的元素平衡并探究体系电子流向。运用同位素示踪，辅以DFT模拟计算揭示原子氢产生、体系加氢脱氯的电子转移机理，为原位、高效、安全的可见光催化净化水体氯代烃提供理论基础。

中文关键词： 可见光；催化还原；氯代烃；Z-scheme；

英文摘要： It is an eager issue to develop a metal catalytic reduction dechlorination system to avoid continuous adding of reductive agent and anaerobic reaction atmosphere. Based on the Z-scheme system in hydrogen evolution from water splitting under visible light, the application focus on combining photocatalysts with metal catalysts to match the band gap of photocatalysts well to trap photogenerated holes by water with oxygen produced simultaneously. The Schottky barrier formed when metal catalysts are deposited on the surface of semiconductor catalysts can facilitate the production of hydrogen atom by donating electron to hydrogen ion. On the basis of the ability to dissolve hydrogen easily, the metal catalysts will be screened and applied to reduce water to hydrogen atom which can be used as an active agent for hydrodechlorination. Accordingly, a new reductive material for photocatalytic reduction dechlorination of chlorinated hydrocarbon can be achieved which will not be affected in the presence of dissolved oxygen in solution. Advanced approaches of catalyst characterization will be employed to investigate the particle size, specific surface area, composition, surface structure, band structure, density of states (DOS), the lifetime and density of the photogenerated charge carriers, and hydrogen surface coverage of

英文关键词： visible light；catalytic reduction；Z-scheme；chlorohydrocarbon；