二元磁性锰基纳米催化剂的构建及其催化KHSO5氧化水中抗生素的效能与机制研究

Sulfate radicals, which is a strongly oxidative species with high selectivity in pH-neutral conditions, exhibits more promising potentials than hydroxyl radicals toward advanced oxidation of organic pollutants in water and wastewater. Heterogeneous peroxymonosulfate catalysis draws an increasing attention by virtue of good selectivity and minimal environmental impact. However, the drawbacks associated with low catalytic efficiency and separation limit its further applications. To address these problems, the present study aims to develop more effective catalyst by fabricating new binary magnetic core-shell nanocomposites, attempting to promote the catalytic formation of sulfate radicals for oxidation of quinolone antibiotics. The project will be carried out through preparing the binary magnetic core-shell nanocomposites made of magnetic core and MnO2 shell with three catalytic active areas including magnetic particles, MnO2 and their joint interface. And then, the relation between micromorphology of nanocomposites and its catalytic efficiency will be founded. On the basis, the catalytic performances are also expected to be further enhanced by triggering ultrasonic, microwave and electrocatalyic methods, which realizes the minimization of chemical dosage and decrease in the total cost. Besides, the study also dedicates to uncover the mechanisms of peroxymonosulfate catalysis in various process and the degradation pathway of quinolone antibiotics according to the intermediate products measurement in antibiotic decomposition.

硫酸根自由基是在中性条件下具有高氧化还原电位和强选择性强氧化性物质，在高级氧化降解水中污染物应用中比羟基自由基更加高效。非均相过硫酸氢钾催化技术具有易于催化、环境危害小的特点，然而目前其存在催化剂难以固液分离、催化效能低等缺陷。针对这些问题，本课题拟构建具有高效催化和快速分离性能的磁性锰基纳米催化剂，研究其催化产生硫酸根自由基氧化去除水中的喹诺酮类抗生素药物的机制和效能。首先，首先，以MnO2为外壳，以磁性氧化物为核心，构建两种组分和组分连接界面三个区域同时具备催化功能的二元磁性纳米核壳材料。然后，通过催化效能比较建立微观形貌和其本身催化性能的构效关系；在此基础上，通过超声、微波、电极等辅助手段同时结合催化剂耦合实现强化催化效能，达到减少药剂投量、降低处理成本的目的。最后，揭示不同催化体系中的催化机理，确定发挥主要氧化功能的自由基，同时精确测定抗生素分解的中间产物，建立抗生素的降解路径。

硫酸根自由基是在中性条件下具有高氧化还原电位和强选择性强氧化性物质，在高级氧化降解水中污染物应用中比羟基自由基更加高效。但是目前的非均相过硫酸氢钾催化剂普遍存在难以固液分离、催化效能低等缺陷。本课题从优化二元催化剂的微观结构入手，通过催化剂组分和组分连接方式优选，强化催化剂界面的电子转移和物质传递，实现过硫酸氢钾的高效催化和污染物的快速降解。首先，制备了Fe3O4-CuO、Fe3O4-FeOOH、Mn3O4-MnO2等两种组分和组分连接界面三个区域同时具备催化功能的二元磁性纳米催化剂，通过催化剂表面的电子快速移动实现了过硫酸氢钾的高效活化，大大提高了污染物的降解效率。其次，借助超声、紫外等能量输入方式，进一步强化了体系中过硫酸氢钾的活化效果。最后，通过ESR检测和淬灭实验确定了不同催化体系中产生的自由基种类和发挥主要氧化作用的自由基，并结合催化剂的微观物化性质的变化确定了催化机理。同时了分析了污染物降解的中间产物，确定了污染物降解路径。本研究为过硫酸氢钾催化剂的微观结构设计提供了理论上的指导，具有一定的学术价值和理论意义。