基于层状杂化体系的复合金属氧化物制备及光解六氯苯的机理研究

本课题基于水滑石材料的结构及催化特性，首先，采用水热合成法制备ZnM1水滑石（M1=Cr, Ce, Sn, Zr）；其次将一类含有阴离子基团的席夫碱与过渡金属元素（M2=Fe, Co, Ni, Ti）进行配位形成金属有机配体阴离子；再者，利用离子交换法使上述配体阴离子取代水滑石的层间硝酸根制备一类层板和层间均含有过渡金属元素的有机无机层状杂化材料；最后将上述材料经微波焙烧，拟制备一类具有特殊晶型、高比表面积、均匀孔径分布和窄禁带宽度的复合金属氧化物光催化材料。拟将上述材料应用于持久性有机污染物六氯苯的可见光降解，同时利用高效液相色谱–质谱联用技术（HPLC–MS）分析降解过程的中间产物，顺磁共振技术（ESR）分析催化过程的活性自由基，据此推断光催化降解的机理，探究催化剂结构组成与其光催化性能之间的关系，从而更好的指导相应光催化材料的合成与应用。

This project will focus on the study of micro–structure and catalytic properties of layered double hydroxides (LDHs), firstly, a series of ZnM1–LDHs (M1=Cr, Ce, Sn, Zr) will be synthesized by hydro–thermal synthetic method, followed by doping M2–containing (M2=Fe, Co, Ni, Ti) Schiff base complex into the interlayer of the ZnM1–LDHs to form a novel layered organic–inorganic hybrid material with transition metals dispersed both in layers and interlayer. And then, the hybrid material will be further calcined by microwave to make metal oxide composites M2/ZnO–M1xOy（M1=Cr, Ce, Sn, Zr；M2=Fe, Co, Ni, Ti）with special crystalline structure, large surface area, uniform pore size distribution and narrow band gap. The prepared materials will be tested by the visible light photocatalytic degradation reaction of hexachlorobenzene (HCB, a type of Persistent Organic Pollutants) for their performance. And the reaction products will be analyzed by going through HPLC–MS instrument to catch the possible intermediates and by ESR to analyze the type of hydroxyl radicals. Based on the information of the activity and the chemical and physical composition of the materials, we will try to figure out the possible reaction pathways, the degradation mechanisms, and the connection between the properties of the materials with their structures. The knowledge generated from this research will be able to guide the future research on high performance photo catalyst synthesis.