银硼（Ag,B)共掺杂TiO2光催化剂活性增强机制的固体核磁共振实验和量化计算研究

项目名称： 银硼（Ag,B)共掺杂TiO2光催化剂活性增强机制的固体核磁共振实验和量化计算研究

项目编号： No.21203240

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： 冯宁东

作者单位： 中国科学院武汉物理与数学研究所

项目金额： 25万元

中文摘要： (Ag,B)共掺杂TiO2是一类新型的光催化材料，其在可见光和太阳光下均表现出良好的光催化活性。本项目拟采用先进的固体NMR技术（多量子、双量子和双共振等技术）结合其它实验手段和量化计算研究该催化剂中活性Ag/B物种的微观结构、分布及其形成机制。结合紫外-可见分光光度法和GC-MS技术探索不同微观结构对光催化性能的影响机制，明确活性物种Ag/B在光催化反应过程中的协同机制。利用原位固体核磁共振技术跟踪有机小分子催化氧化反应历程，观测反应物的在催化剂表面的吸附和转化，揭示催化反应活性位点；结合实验所观测到的中间体以及产物对反应过渡态进行理论计算，从分子水平上阐明(Ag,B)共掺杂TiO2上光催化反应的机理，揭示催化剂活性增强的微观本质，为合成活性高、稳定性好的TiO2光催化材料提供依据。

中文关键词： 固体核磁共振；光催化机理；二氧化钛；量化计算；

英文摘要： It has been found that (Ag, B)-codoped TiO2 photocatalysts exhibit an exceptionally high activity toward photocatalytic oxidation of methylene blue (MB) and rhodamine B (RhB) under visible-light or solar light irradiation, compared with solely (B- or Ag-) doped, and pure TiO2 catalysts. To gain new insights into the structure-activity rlationship, the structure, distribution, and formation mechanism of Ag and B species in the TiO2 photocatalysts will be investigated by advanced solid-state NMR technology (such as multi-quantum (MQ) MAS NMR techniques, double-quantum (DQ) correlation NMR techniques, and double-resonance experiments, etc.) in conjunction with density functional theory (DFT) calculations. Combined with the experiments of photocatalytic activity measured by UV-Vis spectrophotometry and GC-MS, the mechanism of Ag/B synergy can be clarified. To reveal the active site on the surface of the photocatalysts, the adsorption and conversion of the reactants will be studied by the 13C and 17O in-situ solid state NMR techniques, which can be used to track the pathway of photocatalytic oxidation of VOCs, such as alkene, carboxylic acid, and aldehyde. Based on the intermediates and products observed in the in-situ NMR experiments, the transition states of the reaction can be studied by theory calculations, which

英文关键词： solid state NMR；photocatalytic mechanism；titania；Theoretical caculation；