基于纳米功能材料的水体抗生素类污染物去除机理及应用研究

The research based on nanocomposite electrodes for photoelectrocatalysis oxidation removal of pollutants in water is a new direction and economic efficient sewage treatment technology. In this study, we tend to use a two-step method to prepare g-C3N4/3D-TiO2 nanotube arrays and construct a three electrodes photoelectric system to photoelectrocatalytic degradation of quinolones (QNs) under visible light irradiation. Photoelectric coordinating and water environmental factors were studied to optimize photoelectriccatalysis system. The mechanisms for the removal of antibiotic via electro-optic systems are studied with QNs, as the model compound. The hydroxyl radicals are detected with the electron spin resonance spectrometer after the addition of DMPO, to reveal the formation mechanism of the hydroxyl radicals. The reaction sites in the QNs molecule attracted by the hydroxyl radicals and oxidation products are determined with the liquid-chromatography coupled with mass spectrometry. The oxidation pathway of QNs is proposed. Water samples were collected from five sites in the Danjiangkou Reservoir, an important drinking water source in China, and the effectiveness of application is analyzed. The internal relation between microscopic structure and preparation conditions of g-C3N4/3D-TiO2 was illuminated, to realize controllable preparation of morphological structure for g-C3N4/3D-TiO2 nanotube arrays. The finding and out-comings will provide theoretical evidence for the development of enhancement technology in restoring water body quinolones pollution.

基于复合材料电极光电氧化去除水体污染物的技术是经济高效的新型水处理技术。本研究采用两步法可控制备g-C3N4/3D-TiO2纳米管阵列电极，构建三电极光电氧化系统，以喹诺酮类抗生素为模式化合物，揭示拟制备电极g-C3N4/3D-TiO2光电催化去除水体QNs效果及机理。研究光电协调作用及重要水环境因子对光电催化降解QNs的影响与作用机制，以更好地优化系统。检测反应过程产生的羟基自由基，揭示羟基自由基的生成机制，利用液质联用技术分析羟基自由基攻击QNs分子位点和氧化产物，阐明QNs氧化降解途径。采集丹江口水库水样，进行实际应用效果分析。研究将阐明g-C3N4修饰3D-TiO2纳米管微观结构与制备条件之间的内在联系，实现g-C3N4/3D-TiO2纳米管复合材料的形态结构可控制备；从分子水平上深入理解多维结构纳米材料光电催化、吸附等反应机理，实现电极的的功能设计和调控。

近年来，水体环境中的抗生素类有机微污染物问题日益凸显。开发高效的水处理技术应对日益严重的微有机污染物饮水安全问题，已成为全世界亟待解决的科技热点。本项目基于复合纳米材料电极光电氧化去除水体污染物抗生素技术的研究，得到系列研究成果：(1)采用两步法可控制备了g-C3N4/3D-TiO2纳米管阵列电极，构建三电极光电氧化系统，以喹诺酮类抗生素(QNs，环丙沙星、氧氟沙星、加替沙星、莫西沙星)为模式化合物，探讨分析了工作电极g-C3N4/3D-TiO2光电催化去除水体QNs效果及机理分析，从分子水平上深入理解多维结构纳米材料光电催化、吸附等反应机理，实现了电极的功能设计和调控。(2)研究了光电协调作用及重要水环境因子(阴离子、阳离子、尿素等)对光电催化降解QNs的影响与作用机制，将参数应用到光电催化降解污染物系统的优化过程中，模拟抗生素废水的去除可达96%/120min,确定了氧化过程中的氧化物种，并阐明了环丙沙星氧化降解途径。(3)采集丹江口水库和汉江水样，进行了实际应用效果分析，结果表明，将其应用于丹江口水体中喹诺酮类抗生素的去除效果可达93.4%/120min,大型溞急性毒性实验证实，喹诺酮类抗生素的降解中间产物具有低生态毒性，该方法绿色、环保、经济，可利用太阳能资源解决生态水环境问题，有非常好的实际应用开发前景；(4)高催化性能g-C3N4/La-N-TiO2和超磁性Fe3O4纳米材料的可控制备及其应用于CIP的去除研究；(5)在本项目的资助下，发表SCI检索论文1篇，1篇论文投稿《材料导报》已接收，1篇论文投稿《分析化学》审稿中，1篇论文投稿《International Journal of Environmental Research and Public Health》中，2篇论文撰稿。在人才培养方面，共联合协助完成2名硕士生培养，通过答辩，联合协助培养1名博士研究生，预计2023年答辩。