负载型Ag/SiO2/AgMO3（M=Nb，Ta）纳米分级结构构筑及共振增强可见光深度处理含酚废水研究

This project pays attention to the enviromental problems induced by phenolic compounds. By combination of photocatalysis technique, adsorption and theoretical simulation, novel photocatalyst with high adsorption and photo-conversion properties are explored with the aim of removing phenolic compounds from water. By controlling the particle size, morphology of Ag and SiO2, Ag/SiO2/AgMO3 hierarchical structure can be constructed for high visible absorption. Thi can promote the modulation of direct electron transfer, surface plasmon resonance mediated local electromagnetic filed and resonant energy transfer efficiency between Ag nanoparticles and AgMO3 semiconductors. By doping with metal or non-metal ions into AgMO3 host lattice, the band structure of AgMO3 can be moducated to match the visible absorption induced by Ag surface plasmon resonance. by such method, the electron-hole pairs can be effeciently separated for highly enhanced photocatalytic performance. Subsequently, with the idea of "enrichment firstly, catalysis secondly" for phenolic compounds, the as-prepared samples are loaded on carrier of Bentonite, which can raise the responsive concentration of phenolic compounds. Simultaneously, by ultilizing theoretical simulation and characterization, we systematically investigate the influence of doping effects, hierarchical construction on the modulation of band gap energies and photocatalytic activities. This project will not only develop a new type of loaded plasmonic photocatalist with high photocatalytic activities to phenolic compounds, but also provide theoretical and technical support for the application of mixed oxide materials in photocatalytic materials and enviroment purification.

本项目针对内蒙古自治区产业现状，采用光催化、吸附与理论模拟相结合的技术手段，探寻一种高吸附、高光转换效率的光催化剂。通过构筑Ag/SiO2/AgMO3分级结构，调节Ag及SiO2的尺寸、形貌等参数提高可见光吸收，调控Ag与AgMO3间的界面电子转移、局域电磁场耦合效应及能量传递效率；利用掺杂调控AgMO3的能带结构匹配银等离子体共振吸收，提高光生电荷产生及分离效率，改善光催化活性；利用膨润土为载体，采用先富集再催化的理念，提高催化剂对极低浓度酚基化合物的响应；利用计算机模拟和光谱表征相结合的方法，研究掺杂效应、分级结构构筑等对Ag/SiO2/AgMO3的能带隙变化、光谱吸收带边的红移、可见光吸收效率以及光催化活性的影响。本项目的完成，为内蒙古自治区在光催化材料和环境净化技术综合利用提供经验积累，拓宽等离子光催化剂在复合氧化物中的应用范围，预计将开发出具有实际应用前景的新型光催化剂。

本项目针对内蒙古自治区产业现状，采用光催化、吸附与理论模拟相结合的技术手段，探寻一种高吸附、高光转换效率的光催化剂。结果表明：将AgBr担载到AgTaO3上形成的AgTaO3/AgBr异质结在可见光区有很强的吸收，其光催化活性远高于AgTaO3和AgBr。理论计算与实验结果都表明，AgTaO3与AgBr匹配的带结构有利于AgBr和AgTaO3界面电荷迁移，促进光生载流子分离从而提高光催化活性。此外，由于Ag的表面等离子共振效应，三元AgTaO3/AgBr/Ag光催化剂的可见光吸收延长至800nm，表现出很高的稳定性与光催化活性。高温固相法合成AgTa1-xNbxO3材料发现随着x值的增大，AgTa1-xNbxO3的带隙值从3.37 eV减小到2.73 eV。理论计算结果也表明随着x值的增大，带隙值减小，且导带边电势变负。通过水热法合成了Na2Ta2O6/Ag异质结构催化剂，探究Ag+离子掺杂及Ag纳米颗粒的异质结构筑对可见光降解罗丹明B的影响，深入探讨银对Na2Ta2O6的电子结构、缺陷化学以及可见光催化性能的调控作用。Ag/Sr0.25H1.5Ta2O6•H2O/g-C3N4 、Ag/SrTa2O6/g-C3N4系列复合光催化剂在在可见光照射下对Cr(VI)的还原以及甲基橙的降解比单相Sr0.25H1.5Ta2O6•H2O和g-C3N4催化剂表现出了更高的光催化活性。由于Ag的表面等离子共振效应，Ag/Sr0.25H1.5Ta2O6•H2O/g-C3N4 、Ag/SrTa2O6/g-C3N4系列光催化剂的可见光吸收延长至800nm，表现出很高的稳定性与光催化活性。制备了Bi0-BiSbO4纳米结构，发现其对还原硝基苯成氨基苯类催化还原反应显示有高的活性。另外，光照可以促进Bi3+向金属铋的还原，这就大大提高了硝基苯还原为氨基苯的反应速率。.本项目的实施开发出一系列用于光催化降解有机污染物的宽光谱响应范围的等离子体光催化材料，其各项性能均有明显提升，为等离子体基光催化材料在能源转化和环境净化方面的综合利用提供可能。因此本项目的实施无论在理论研究还是潜在应用方面都有重要意义。