三维多孔石墨烯包裹纳米零价铁双金属的制备及其类Fenton氧化水中抗生素研究

The antibiotics residues in the environmental samples have become a serious problem, which need to be treated by advanced technologies. To improve the removal efficiency of heterogeneous Fenton-like system as well as to solve the problem of catalyst deactivation caused by the leaching of active components from the catalyst surface, three-dimensional porous graphene wrapped nanoscaled bimetals based on zero-valent iron (M0@3DGN) will be prepared, which will be used to remove antibiotics in water. The catalysts are synthesized by chemical reduction and self-assembly of graphene oxide, and the effect of various synthesis conditions on the adsorption activity, Fenton-like catalytic activity and stability is investigated. The synergistic effect of active components is studied. The removal of chloramphenicol, sulfadiazine and trimethoprim is investigated, and the influence of key factors on adsorption and Fenton-like oxidation is studied. The mechanisms of adsorption and Fenton-like oxidation are illustrated, and the degradation pathway of antibiotics is deduced by the detection of intermediates and the identification of active species. The method of density functional theory (DFT) is applied to analyze the adsorption site and the adsorption energy, as well as to further propose the degradation pathway of antibiotics, intermediates and rate-determining step. Therefore, the relationship between the microstructures of M0@3DGN and the catalyst activities is established. These results will provide the foundation for the development and application of novel heterogeneous Fenton-like catalysts, and point toward an available method for the removal of antibiotics in water.

针对日益突出的抗生素污染问题，为提高非均相类Fenton法的去除效果并解决催化剂稳定性问题，本项目拟制备三维多孔石墨烯包裹纳米零价铁双金属（M0@3DGN）材料并用于去除水中抗生素。拟采用化学还原自组装法制备M0@3DGN，研究制备条件对吸附性能、类Fenton氧化性能和稳定性的影响规律，并揭示催化剂各组分的协同作用机制。以氯霉素、磺胺嘧啶和甲氧苄氨嘧啶为典型抗生素污染物，明确影响吸附效率和类Fenton氧化效率的关键因素，阐明吸附机理及类Fenton催化氧化机理；识别活性物种和降解产物，揭示抗生素的降解途径。采用DFT法获得材料表面的吸附位点和吸附能，得到抗生素在氧化体系中的反应路径、过渡态中间产物、关键限速步骤等，最终揭示M0@3DGN微观结构及其性能的“构–效”关系。预期成果可为非均相类Fenton催化剂的研发与工程应用提供科学依据，为深度处理水中抗生素的技术发展提供重要的理论基础。

针对抗生素污染问题，提高催化剂的活性和稳定性是非均相类Fenton法的重要研究方向之一。本研究筛选和制备了一系列三维多孔石墨烯包裹纳米铁双金属材料（包括3DGN@nZVI、3DGN@Cu0、3DGN@Fe/Cu、3DGN@Fe/Al和3DGN@Fe/Mn），考察了还原工艺、还原时间、还原剂浓度、双金属配比等因素对复合材料的微观形貌、物理化学性能和催化活性的影响，建立了催化剂合成工艺与催化性能之间的关系，有效调控形貌结构和催化性能。研究了该系列催化剂对磺胺嘧啶、甲硝唑、氯霉素等抗生素的吸附性能、类Fenton氧化性能和稳定性，考察了溶液pH值、温度、催化剂用量、抗生素浓度等因素的影响，分析了反应动力学和热力学；具体解析了催化剂表面缺陷、电荷分布、电子转移过程、轨道能级、以及氧化还原反应性能，确认了活性组分的作用，提出了微电池-类Fenton反应协同作用机制。结合实验与计算，明确了抗生素的结构性质、福井函数和易受攻击的反应位点，阐明了磺胺嘧啶、甲硝唑、氯霉素等抗生素的降解路径，包括醇基氧化、苯环加成反应、抽氢反应、水解反应、脱硫和脱氮反应等。该系列催化剂拓宽了pH应用范围，并且仅利用溶液中的饱和溶解氧发生Fenton反应高效去除水中抗生素，具有潜在的应用价值；将实验手段和计算模拟有机结合起来，可为有机污染物的降解机理研究提供参考和指导。