双电层效应电吸附材料的构造及离子分离机理

The separation of aqueous heavy metal ions is crucial to the control of heavy metal pollution and the recycling of heavy metal resources. The traditional electrosorption technology, which can adsorb ions and store them in the electric double layer region through electrostatic interaction, fails in separating ions that with different characteristics. However, the separation of ions can be realized by the ion separation method based on the fine structure of the electric double layer. Till now, to optimize the design of these electrode materials and to clarify the relationship between the fine structure of the electric double layer and the ion separation efficiency, are the key problems that have not been solved. Herein, we propose to design nitrogen-doped graphene, which can optimize the fine structure of the electric double layer; The chemical form and amount of nitrogen will be tuned to improve the fine structure effect of the electric double layer and the relationship between the chemical form of nitrogen and the characteristics of the fine structure of the electric double layer will be clarified. The mechanism on the formation/transformation of the fine structure of the electric double layer will be proposed. The method of tuning the stability and ion selective ability of the fine structure of the electric double layer will be developed. The water treatment technology and reactor based on this ion separation method will also be exploited. The project will provide scientific basis and theoretical fundamentals for the innovation in the control of heavy metal pollution and the recycling of heavy metal resources.

如何有效分离出水中重金属离子是控制重金属污染和实现重金属资源回收利用的关键步骤。现有的电吸附技术是通过静电作用将水中离子吸附在双电层中，而不具备将多种金属离子分离的功能。基于双电层精细结构效应的离子分离方法可实现对水中不同离子的高效分离。然而，如何构建并优化具备双电层精细结构效应的电极材料，阐明双电层精细结构与离子分离效能之间的关系，是研究中尚未解决的核心问题。为此，本项目提出构建具有双电层精细结构效应的氮掺杂石墨烯；通过调控掺氮形态和掺氮量，提升双电层精细结构效应，明确掺氮形态和双电层精细结构特征的匹配关系；揭示双电层精细结构效应的作用机理与形成/转化机制，提出双电层精细结构的稳定性与离子选择性的调控方法，发展基于双电层精细结构效应的净水方法与反应器，为重金属污染控制和资源回收技术的创新和应用提供科学依据和理论基础。

如何有效转化、分离出水中重金属离子是控制重金属污染和实现重金属资源回收利用的关键步骤。本研究从分子尺度、微纳米尺度等对电极材料进行功能和结构调控，研究了水中污染物电分离与电转化的多相反应过程，建立了基于界面构造及微物理场调控的电化学新原理和新方法。通过构建具有双电层精细结构效应的氮掺杂石墨烯，明确了掺氮形态和金属离子选择性吸附的匹配关系，揭示了孔结构特征对离子选择分离的影响机制，提出了基于氮形态和孔结构调控的高效离子分离电极材料的设计思路与方法；研究了电化学反应过程的微场强化作用，研发了聚苯胺纳米点修饰石墨烯电极，并开发了微流体穿过式电化学反应器，实现对六价铬的高效还原；进一步构建了聚苯胺/石墨烯复合材料和铁还原电池系统，实现六价铬还原并同步产电；研制了高性能Pd-In双金属电催化剂，耦合穿透式电极反应器，通过流场强化和电荷调控实现活性物种原子氢的稳定和高效利用，并提出微结构调控界面传质以及活性物种有效产生与利用的策略。本研究提出的基于界面构造调控重金属离子的高效吸附、分离和转化，为重金属污染控制和资源回收技术的创新提供了理论基础。