金属-有机框架固载离子液体对无机含氧阴离子污染物的分离/富集

Water pollution caused by inorganic oxyanion pollutants from industrial wastewater is increasingly serious. Ion exchange, as a cost-effective and eco-friendly strategy for the removal of these pollutants, has attracted considerable research attention. In this project, thermally and chemically stable MOFs, such as UiO (UiO-66, UiO-67 and UiO-68), M-MOF-74 （M = Mg, Mn, Co, Ni, Zn） and ZIF-8, will be selected to immobilize [RMI][NO3] or [RPy][NO3] ionic liquids (ILs) (RMI = 1-alkyl-3-methylimidazolium; RPy = N-alkyl pyridinium; R = ethyl, propyl, butyl, amyl, or hexyl). The resulting ILs@MOFs will be employed in the separation and enrichment of inorganic oxyanion pollutants, by exchange of the ILs anions incorporated within the micropores of a MOF which are easy to be swapped out. The relationship between the proportion of ILs and MOFs and the exchange capacity of the targeted anion will be studied systematically. The crucial aim of this project is to explore the influence of the structure of MOFs and the kinds of ILs on the adsorption–desorption of the targeted anion, such as the size and type of micropore, center metal ion species, and the kind and size of IL cation. From these studies, we hope to establish controllable syntheses of ILs@MOFs with the separation and enrichment of the targeted anion, reveal the adsorption–desorption mechanism of the targeted anion. It is expected that our research can provide a new way for the removal of inorganic oxyanion pollutants, and collect some experimental and theoretic facts for further developments and applications of ILs@MOFs materials.

无机含氧阴离子污染物造成的水污染问题日益严重。离子交换法具有成本效率高、环境友好的优势，受到广泛关注。本项目以稳定性好的UiO和M-MOF-74系列以及ZIF-8为载体，通过固载1-烷基-3-甲基咪唑硝酸盐或N-烷基吡啶硝酸盐来合成ILs@MOFs材料，利用ILs@MOFs中的ILs阴离子易于被交换出去的特性，开展ILs@MOFs材料在无机含氧阴离子分离/富集方面的应用。系统研究ILs与MOFs的比例和目标阴离子交换容量之间的关系，探索MOFs孔洞尺寸大小、类型、中心金属离子种类以及ILs阳离子的种类和大小对目标阴离子吸附和脱附的影响规律，建立可控合成具有分离/富集目标阴离子功能的ILs@MOFs材料的方法，为研究ILs@MOFs材料对目标阴离子吸附及脱附机理奠定基础。本项目不仅为无机含氧阴离子污染物的分离/富集提供一条新的途径，而且也可以为ILs@MOFs材料的应用研究提供有价值的信息。

本项目开展了阳离子型MOFs材料的合成及其对阴离子的吸附研究、咪唑类离子液体导向的新颖多功能MOFs材料的合成及其性能研究、MOFs限域热解ILs制备掺杂型碳点复合材料（CDs@MOFs）等研究工作。获得一种含游离NO3-离子的多孔阳离子型MOF材料，可基于单晶-单晶转变方式吸附和脱附铬酸根离子；咪唑类离子液体导向合成稳定的MOFs材料可用于环境检测硝基芳香化合物和抗生物；CDs@MOFs复合材料或可实现系统调控CDs发光带隙和CDs固态高效发光。本项目成功制得了MOFs固载ILs复合材料（ILs@MOFs），但是ILs@MOFs对阴离子的吸附没有呈现出明显的规律性，难以总结ILs@MOFs材料的组成对阴离子吸附的影响规律及吸附机理。项目研究期间，在《Chem. Commun》和《Dalton Trans》发表2篇论文，授权国家发明专利1 项，获河南省自然科学学术论文一等奖1项，培养硕士研究生2名。