Pyridinium salt-based covalent organic framework with well-defined nanochannels for efficient and selective capture of aqueous^(99)TcO_(4)^(-)  

联吡啶嗡盐共价有机框架材料合成与选择性捕获放射性高鍀酸根

作　　者：Mengjie Hao Zhongshan Chen Hui Yang Geoffrey I.N.Waterhouse Shengqian Ma Xiangke Wang 

机构地区：[1]College of Environmental Science and Engineering,North China Electric Power University,Beijing 102206,China [2]MacDiarmid Institute for Advanced Materials and Nanotechnology,School of Chemical Sciences,The University of Auckland,Auckland 1142,New Zealand [3]Department of Chemistry,University of North Texas,Denton,TX 76201,USA

出　　处：《Science Bulletin》2022年第9期924-932,M0004,共10页科学通报（英文版）

基　　金：supported by the National Natural Science Foundation of China(U2167218 and 22006036);the National Key Research and Development Program of China(2017YFA0207002 and 2018YFC1900105);the Science Challenge Project(TZ2016004);the Beijing Outstanding Young Scientist Program(H.Y.and X.W.);the Robert A.Welch Foundation(B-0027)(S.M.)。

摘　　要：Ionic covalent organic framework(COF)materials with high specific surface areas and well-defined pore structures are desired for many applications yet seldom reported.Herein,we report a cationic pyridinium salt-based COF(PS-COF-1)with a Brunauer-Emmett-Teller(BET)surface area of 2703 m^(2) g^(-1),state-ofthe-art for an ionic COF.Aided by its ordered pore structure,chemical stability,and radiation resistance,PS-COF-1 showed exceptional adsorption properties toward aqueous ReO_(4)^(-)(1262 mg g^(-1))and ^(99)TcO_(4)^(-).Its adsorption performance surpassed its corresponding amorphous analogue.Importantly,PS-COF-1 exhibited fast adsorption kinetics,high adsorption capacities,and selectivity for ^(99)TcO_(4)^(-)and ReO_(4)^(-)at high ionic strengths,leading to the successful removal of ^(99)TcO_(4)^(-)under conditions relevant to low-activity waste streams at US legacy Hanford nuclear sites.In addition,PS-COF-1 can rapidly decontaminate ReO_(4)^(-)/^(99)TcO_(4)^(-)polluted potable water(~10 ppb)to drinking water level(0 ppb,part per billion)within 10 min.Density functional theory(DFT)calculations revealed PS-COF-1 has a strong affinity for ReO_(4)^(-)and ^(99)TcO_(4)^(-),thereby favoring adsorption of these low charge density anions over other common anions(e.g.,Cl^(-),NO_(3)^(-),SO_(4)^(2-),CO_(3)^(2-)).Our work demonstrates a novel cationic COF sorbent for selective radionuclide capture and legacy nuclear waste management.具有高比表面积及规则孔道结构的离子型共价有机框架(COF)材料表现出广泛的应用前景.本文设计合成了一种基于联吡啶嗡盐的阳离子型COF材料(PS-COF-1).PS-COF-1比表面积为2703 m^(2) g^(-1),高于目前报道的其他离子型COF材料.PS-COF-1具有固定的一维通道(~4.5 nm)、良好的化学稳定性和耐辐照稳定性,表现出优异的吸附ReO_(4)^(-)(最大吸附量为1262 mg g^(-1))和^(99)TcO_(4)^(-)性能.进一步研究表明,PS-COF-1在高离子强度下表现出快速吸附动力学、高吸附容量和对^(99)TcO_(4)^(-)和ReO_(4)^(-)的高选择性,在模拟美国汉福德低活性废物流条件下成功选择性去除了^(99)TcO_(4)^(-).此外,PS-COF-1能够在10 min内将ReO_(4)^(-)和^(99)TcO_(4)^(-)污染水净化至饮用水级别.密度泛函理论计算表明,PS-COF-1对低电荷密度阴离子ReO_(4)^(-)和^(99)TcO_(4)^(-)具有强的亲和力(优于其他常见阴离子,如Cl^(-),NO_(3)^(-),SO_(4)^(2-),CO_(3)^(2-)),阐明了PS-COF-选择性吸附^(99)TcO_(4)^(-)的机理.本文展示了一种用于选择性捕获放射性核素新型阳离子COF吸附剂,为放射性污染治理提供了重要的理论依据和指导.

关 键 词：PERRHENATE PERTECHNETATE Covalent organic frameworks Environmental remediation Anion exchange 

分 类 号：X591[环境科学与工程—环境工程] TQ424[化学工程]