基于MOFs的三维多孔电极在生物电化学系统中去除染料废水效能及降解机制

Bio-electrochemical system is an effective technology to treating dye water during the energy shortage and environmental pollution. The activity, durability and cost-efficiency of electrode materials mainly restrict the development and application of bio-electrochemical system. Metal-organic frameworks (MOFs), which have open, topology structure, high surface area and porosity, showed potential research value and broad application prospect in the treatment of refractory organic wastewater. The present project will focus on the dye degradation mechanisms of adsorption-electrocatalysis process on three-dimensional (3D) porous electrode derived from MOFs in bio-electrochemical system as the key scientific problem. The main works to be performed in this project including the preparation and characterization of electrode materials, mechanisms of dye degradation, regulation synthesis of 3D porous electrode derived from bimetallic MOFs. Then, efforts will be emerged on identification of the structure-activity relationship between the surface structure, active groups and dye degradation, mechanisms of adsorption-electrocatalysis on the materials. The last task is to investigate the impact of degradation performances by the key factors such as electrode surface structure, solution pH, co-existing cations and anions. This research not only suggests the fundamental mechanisms for adsorption-electrocatalysis degradation of dye and optimization bio-electrochemical system design and operation, but also provides new strategies and methods to develop high-efficiency, high-stability, sustainable electrode materials and green bio-electrochemcial process for wastewater treatment and biomass utilization.

针对能源危机与环境污染问题，生物电化学技术是处理染料废水的有效方法之一。电极材料的活性、稳定性和经济性制约着生物电化学技术的发展和应用。金属有机框架是一类具有开放式拓扑结构、大比表面积和孔隙率的新型多孔材料，在难降解有机废水处理中具有潜在的研究价值和广阔的应用前景。本项目围绕“三维多孔材料在生物电化学系统中对染料的吸附-电催化降解的构效关系”这一关键科学问题，开展电极材料制备、性能表征、降解机制解析的研究，探究基于双金属有机框架材料的三维多孔电极的可控合成，识别电极的表面结构和活性基团与染料在其表面的吸附-电催化降解过程的构效关系和降解机制，探索电极表面结构、溶液pH、离子强度等关键影响因子的影响机制。本项目不但为深入认识染料在生物电化学系统的吸附-电催化降解作用规律和优化生物电化学系统设计和运行提供了理论依据，而且为发展高效、稳定、绿色的难降解废水处理和生物质能利用提供了新思路和新方法。

生物电化学系统（BES）技术能够在降解有机污染物的同时将污染物蕴含的化学能转化为电能，其阴极电极材料及BES的扩展应用仍是BES的重要研究方向之一。研究以降低阴极催化剂成本、提高对染料的处理效能、解析染料降解机制为目标，提出了基于金属有机框架结构构建多孔电极材料，探究了对染料的吸附和降解效能，研究了双金属调控催化剂结构形貌对染料的吸附及在BES中吸附-降解染料的效能，并基于生物质构建了廉价多孔催化剂，降低BES电极成本，提高BES产电效能。以金属有机框架材料ZIF-67为前驱体，制备具有磁性的多孔材料的作为高效吸附材料，实现对染料的高效吸附和快速分离。通过动力学和热力学模型解析了吸附机制。以泡沫镍为骨架，通过原位生长的方式在泡沫镍上生成金属有机框架材料ZIF-67，制得三维多孔电极NF/ZIF-67，通过构建三维结构的高效催化材料，强化了染料在催化剂上的吸附过程并提高催化降解效能。以钴基和锌基金属有机框架材料ZIF为前驱体，制备具有可调控的多孔材料的作为高效吸附材料，实现对阳离子型和阴离子型染料的高效吸附和快速分离。金属有机框架衍生多孔材料可通过双金属源进行比表面积和孔道调控，提高吸附材料对不同类型染料的吸附作用，并通过多孔材料的表面带电性，选择性吸附阳离子或阴离子类型的染料，解析了多孔材料结构与染料吸附之间的构效关系。研究中采用可广泛获取、廉价的生物质制备多孔催化剂材料，在生物电化学系统中高效产电。通过直接碳化的形式制备得到了氮掺杂多孔碳催化剂，氮掺杂可明显降低电荷转移电阻，增加ORR活性位点，提高催化ORR能力，在生物电化学系统中获得了较高的产电能力，利于耦合降解体系实现对染料等难降解物质的有效去除。

内容获取失败，请点击重试