共价有机框架材料功能化策略及其对Hg(Ⅱ)和Cr(Ⅵ)的吸附性能研究进展

Research progress on functionalization strategies of covalent organic frame materials and its adsorption properties for Hg(Ⅱ)and Cr(Ⅵ)

共价有机框架(COFs)是一类新兴的多孔晶体聚合物材料,具有出色的结构规则性、高度有序的孔径大小、固有的孔隙率、巨大的比表面积、丰富的活性官能团,使其成为吸附水体中各种污染物的理想材料。本文从COFs的拓扑结构设计和孔隙结构设计角度出发,梳理了COFs结构设计要点,而后分析了侧基功能化、官能团转换和骨架功能化等COFs功能化策略,重点阐述了含N、S、O、Fe(0)、Ag(0)等活性官能团、金属/非金属节点对COFs多孔性、水稳定性、吸附性的影响,而后介绍了COFs在去除重金属离子方面的研究进展,详细介绍了COFs对水中典型重金属离子Hg(Ⅱ)和Cr(Ⅵ)的吸附性能,并结合密度泛函理论阐述COFs去除水中重金属离子的作用机理。最后,总结了COFs的功能化策略及功能化COFs作为高性能吸附剂的技术优势,并分析了目前存在的问题,展望未来发展方向,以期对COFs的制备与应用提供参考。

Covalent organic frameworks(COFs)are an emerging class of porous crystalline polymeric materials with excellent structural regularity,highly ordered pore size,inherent porosity,huge specific surface area,and abundant active functional groups,which make them ideal materials for adsorption of various pollutants in waste water.From the perspective of topological and pore structure design of COFs,this paper sorted out the key points of COFs structural design.Then,the COFs functional strategy such as side group functionalization,functional group conversion and skeleton functionalization was analyzed,focusing on the impact of active functional groups such as N,S,O,Fe(0),Ag(0),and metal/non-metal nodes on the porosity,water stability and adsorption properties of COFs.Then,the research progress of COFs in the removal of heavy metal ions was introduced,the adsorption performance of COFs on typical heavy metal ions Hg(Ⅱ)and Cr(Ⅵ)in water was analyzed and the mechanism of COFs to remove heavy metal ions in water was explained in combination with density functional theory.Finally,the functionalization strategy of COFs and the technical advantages of functionalized COFs as high-performance adsorbents were summarized,the existing problems were analyzed,and the future development direction was expected to provide reference for the preparation and application of COFs.