The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
The School of Chemical, Biological and Materials Engineering and the School of Civil Engineering and Environmental Science, the University of Oklahoma, Norman, OK, 73019, USA.
Nat Commun. 2020 Aug 7;11(1):3947. doi: 10.1038/s41467-020-17757-6.
Herein, we present a scalable approach for the synthesis of a hydrogen-bonded organic-inorganic framework via coordination-driven supramolecular chemistry, for efficient remediation of trace heavy metal ions from water. In particular, using copper as our model ion of interest and inspired by nature's use of histidine residues within the active sites of various copper binding proteins, we design a framework featuring pendant imidazole rings and copper-chelating salicylaldoxime, known as zinc imidazole salicylaldoxime supramolecule. This material is water-stable and exhibits unprecedented adsorption kinetics, up to 50 times faster than state-of-the-art materials for selective copper ion capture from water. Furthermore, selective copper removal is achieved using this material in a pH range that was proven ineffective with previously reported metal-organic frameworks. Molecular dynamics simulations show that this supramolecule can reversibly breathe water through lattice expansion and contraction, and that water is initially transported into the lattice through hopping between hydrogen-bond sites.
在此，我们提出了一种通过配位驱动的超分子化学合成氢键有机-无机框架的可扩展方法，用于从水中有效去除痕量重金属离子。具体来说，我们以铜作为感兴趣的模型离子，并受自然界在各种铜结合蛋白的活性位点中使用组氨酸残基的启发，设计了一种具有悬垂咪唑环和铜螯合水杨醛肟的框架，称为锌咪唑水杨醛肟超分子。这种材料具有良好的水稳定性，并表现出前所未有的吸附动力学，其选择性铜离子吸附速率比现有先进材料快 50 倍以上。此外，使用这种材料在 pH 值范围内实现了选择性去除铜，而之前报道的金属-有机框架在该 pH 值范围内效果不佳。分子动力学模拟表明，这种超分子可以通过晶格的膨胀和收缩来可逆地呼吸水，并且水最初通过氢键位点之间的跳跃进入晶格。
