MOFs衍生一维催化材料对水中微污染物的降解效能与机制

Removal of micropollutants from aqueous solution with high efficiency is a crucial issue in drinking water safety and wastewater reusing area. In order to address the challenges of environmental nanosized catalysts in engineering application, i.e., difficulty in recycle and environmental toxicity, this project dedicates to investigating the construction of one dimensional catalytic materials derived from metal organic frameworks (MOFs) and further exploring the degradation efficiency and mechanism for micropollutants from water in advanced oxidation processes. Based on the essential factors (composition and structure) for catalysts, the iron (cobalt) containing MOFs nanocrystals will be introduced to electrospinning system. After pyrolysis, one dimensional porous carbon nanofibers containing iron (cobalt) along with micropores and mesopores, graphical structure and rich nitrogen content, will be obtained. The regulation and controlling on the morphology, active constituent and hierarchical structure of one dimensional catalytic materials will be investigated. The emphasis will be focused on the mechanism of catalytic removal of typical micropollutants (tetracycline, bisphenol A and benzotriazole) by activating sulfate radical on one dimensional fibers. The adsorption/degradation behavior of target micropollutants, the relationship between the removal efficient and the structure of one dimensional fibers will be systematically studied. The adsorption/desorption behavior and electron transfer pathway on the surface and interface on the active species will be elucidated. Finally, the degradation mechanism for micropollutants on one dimensional catalytic materials will be revealed. Through understanding these scientific issues derived from engineering application, it should be possible to offer technical support for the engineering application of nanosized catalytic materials on advanced oxidation processes.

微污染物的高效去除是当前饮用水安全和污水回用领域的重要课题。针对环境纳米催化材料工程化应用面临的回收难及潜在环境毒性的技术挑战，本项目提出构筑金属有机骨架 (MOFs)衍生一维催化材料并开展其对水中典型微污染物降解效能与机制的研究设想。从组成和结构这两个影响催化剂本征性能的要素出发，将铁(钴)MOFs引入到静电纺丝体系，热解获得微/介孔兼具、石墨化并存、氮含量高的载铁(钴)多级孔碳纳米纤维。探究一维催化材料形貌、活性物种组分及孔结构调变规律，重点围绕其催化过硫酸盐降解水中典型微污染物（四环素、双酚A和苯并三氮唑）的效能与机制展开研究。通过考察目标污染物吸附降解及转化行为，探索一维催化材料组成结构调变与目标污染物协同去除间的相关规律；阐明高级氧化过程中活性物种表界面上吸/脱附行为、电子传递途径，揭示目标污染物降解机制。通过这些科学问题的认知，可望为纳米催化材料的水处理工程实践提供技术支撑。

本项目针对环境纳米催化材料工程化应用面临的技术难题，开展了金属有机骨架（MOF）衍生一维催化材料的构筑及其对水中典型微污染物降解效能和机制的研究工作。从组成和结构两个要素出发，通过“静电纺丝+原位热解”策略构建了高性能0D-1D纳米纤维，实现了材料活性和稳定性同步提高，打破了传统成型过程中性能下降的壁垒；研究了一维催化材料在制备过程中的组成及结构调变规律，揭示限域碳化过程中多级孔碳纳米纤维的形成机理，实现了一维催化材料的形貌、活性物种成分以及多级孔结构的有效控制；从去除机制角度出发，诠释催化剂结构与目标污染物高效去除的构效关系，实现了一维催化材料对目标污染物的增效去除；探究一维催化材料上活性物种在降解目标污染物历程中的表面/界面形态变化，目标污染物的吸附/降解行为及其在活性物种界面处的电子转移途径，评价一维催化材料不同水质环境条件下对典型目标污染物（四环素，双酚A和苯并三氮唑）的去除效果，阐明目标污染物降解机理；通过这些科学问题的研究与探索，获得了纳米负载一维催化材料的构筑方法以及结构调控手段，实现了难降解微污染物的深度去除，在其制备、结构调控和应用方面取得了系列研究成果。在本项目资助下共发表学术论文42篇，其中SCI收录39篇（一区26篇，二区13篇），1篇入选中国百篇最具影响国际学术论文(2019)，5篇论文先后入选ESI热点/高被引论文，影响因子8.0以上有36篇，7篇论文被遴选为内封底/面论文，刊物包括Angewandte Chemie International Edition，Environmental Science & Technology，Water Research，Advanced Science，Chemical Engineering Journal，Journal of Hazardous Materials等。申报国家发明专利7项，2项授权；培养博士研究生6名（其中1名入选江苏省优秀博士论文），培养硕士研究生7名；项目相关成果获省部级奖励2项。指导博士研究生获高廷耀环保科技发展基金会“青年博士生杰出人才奖学金”1项、“南京大学全兴环境基金优秀学子奖”1项、“奥加诺（水质与水环境）”奖学金1项、“北京大学唐孝炎环境科学创新奖学金”1项。指导的博士研究生入选2020年博士后创新人才计划。较好地完成了项目申请书中的成果要求。