MOF材料在水环境污染物去除方面的应用现状及发展趋势(Ⅰ)

Review of application of MOF materials for removal of environmental pollutants from water(Ⅰ)

金属有机骨架(Metal-organic frameworks,MOFs)是一类有机-无机杂化材料,通常是指金属离子或金属簇与含氮、氧刚性有机配体通过自组装过程形成的功能性多孔材料.MOF材料具有丰富的可设计的结构类型、可调控的化学功能、低密度的骨架、超高的比表面积,以及可功能化的永久的孔空间,在气体存储与分离、催化、传感、药物运输与缓释等领域都有广泛的应用潜力.近年来,MOF及其复合材料已经被应用于多种污染物的去除.本文对近年来MOF材料去除水环境中重金属、有机物的相关研究进行了总结与评述.本篇是该主题的第一篇,主要针对MOF材料在水体重金属污染物去除方面的研究进行论述.通过对以往的研究分析可知,MOF材料对常见重金属Pb2+、Cu2+、Cd2+、Co2+、Ag+、Cs+、Sr2+、Hg(II)以及TcO4-、Se(VI)、As(III)、As(V)均具有高效吸附性能,甚至部分MOF材料的吸附性能远高于传统吸附材料.主要的吸附机理包括:静电引力、配位/螯合作用、离子交换作用、孔道吸附(物理吸附)等.最后,基于以往的研究成果对未来的研究趋势进行了展望.

Metal-organic frameworks(MOFs) are a class of organic–inorganic hybrid functional materials that are generally formed via the self-assembly of metal ions or metal clusters and rigid organic ligands with nitrogen and oxygen atoms. A wide range of potential applications for MOF materials includes gas storage and separation, catalysis, sensing, and drug transportation and release, which is attributable to their versatile designable structures, modifiable chemical functionality, low-density frameworks, large specific surface areas,and functional and permanent pore space.In the past decade,MOFs and their composite materials have also been employed to remove various contaminants from the environment.This paper presented the significant research progress and outcomes achieved using MOF materials in the removal of environmental pollutants from water,based on a review of related studies regarding the removal of heavy metals and organic pollutants from water environments.This represented the first part of a larger paper in which the progress of MOF materials research was presented with respect to the removal of heavy metals from aqueous solution.The presence of heavy metals in water is a global environmental issue that has been receiving considerable attention worldwide.According to previous research reports,MOF materials have high adsorption capacities for common heavy metals,such as Pb+2,Hg(II),TcSe(VI),As(III),and As(V).Some MOF materials have even higher adsorption capacities than conventional adsorbent materials.The adsorption mechanism mainly involves electrostatic attraction,coordination/chelation,ion exchange,and pore adsorption(physical adsorption).Based on a review of previous studies,it is believed that the future research field includes but is not limited to the following:(1)the structure–activity relationship between the MOF structure and heavy-metal removal,(2)the functionalization,surface modification,and pore size adjustment technology of MOF,or the preparation of composite MOF materials,(3)further study of the regulation of the defect structures of MOFs to develop new MOF materials with higher adsorption efficiency,(4)improving the recyclability of MOF materials,and(5)developing new MOF materials with high structural stability,high adsorption capacities,high selectivity,low cost,and which are easily reused.