介电泳复合法构建3D耦合电极及其光电降解水体中塑化剂污染物的研究

Organic pollutant is one of the most serious problems of water pollution. Photo-electrochemical catalytic degradation of organic pollutants has been shown to be effective method. The key point is to find active, stable and inexpensive catalysts and study of the mechanism. This project is planned to combine the sol-gel and dielectrophoresis method to synthesis 3D-TiO2-nanotube arrays coupled with CeO2 nanoparticles with different size by using Ti mesh as substrate based on our previous work. The coupled electrode will be stable by in situ synthesis and used as anode directly. Thus a photo-electrochemical system is established. Phthalic Acid Esters (PAEs) is chosen as a model compound. Oxidation mechanism of PAEs is investigated systematically though degradation pathway. The photo-electrochemical oxidation system constructed in the present study is not only efficient but also economic which show great potential for widely application of photo-electrochemical oxidation method for organic pollutants treatment.

有机污染物是水体污染里最严重的问题之一，而传统的污水处理技术还难以达到理想的处理有机污染物的效果。光电催化已被证实是有效去污方法，其关键是制备高效、稳定、廉价的催化电极材料和明确反应机制。本项目拟在前期研究工作基础上，将具有更大比表面积的钛丝网做为电极基底生成3D-TiO2纳米管阵列，然后采用介电泳-溶胶凝胶联用技术原位耦合CeO2纳米晶构成复合电极，拓展光吸收范围，进一步提高其光电催化性能。并以此电极材料为阳极建立光电系统，选取水环境中普遍存在的典型塑化剂邻苯二甲酸酯(Phthalic Acid Esters, PAEs)为模式化合物，通过PAEs在不同条件下的去除效果分析，明确电极构效关系和光电协同作用机制；检测降解中间产物，揭示污染物的光电降解机理，期望在合成高效新型电极材料的同时，开发经济实用的光电化学氧化系统降解有机污染，为改善水体水质以及光电技术的工业化应用提供理论和实验依据。

此项目将具有更大比表面积的钛丝网做为电极基底原位氧化生成3D-TiO2纳米管阵列，具有三维构型，灵活性好、透明度高、比表面积大，对入射光的角度依赖性低。而且，丝网结构透光透水，有利于反应物与产物的快速传输流动。且采用介电泳/溶胶凝胶联用技术合成复合电极材料，通过控制电压、频率、反应时间等操控半导体颗粒在三维TiO2纳米管阵列上定向、有序、可控排列，提高了负载颗粒的分散度与稳定性，进而增强光电催化性能。以染料亚甲基蓝、抗生素和塑化剂类化合物中具有代表性的邻苯二甲酸二甲酯作为模式有机污染化合物，通过优化反应条件，明确电极材料的构效关系以及光电协同的作用机制；通过降解中间产物分析，推测可能的降解途径，明确了系统中有机污染物的降解机理。