Cao Zhonglin, Liu Vincent, Barati Farimani Amir
Department of Mechanical Engineering and Biomedical Engineering , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States.
Nano Lett. 2019 Dec 11;19(12):8638-8643. doi: 10.1021/acs.nanolett.9b03225. Epub 2019 Nov 6.
Providing fresh and drinkable water is a grand challenge the world is facing today. Development in nanomaterials can create possibilities of using energy-efficient nanoporous materials for water desalination. In this work, we demonstrated that ultrathin conductive metal-organic framework (MOF) is capable of efficiently rejecting ions while giving access to high water flux. Through molecular dynamic simulation, we discovered perfect ion rejection rate by two-dimensional (2D) multilayer MOF. The naturally porous structure of 2D MOF enables significantly 3-6 orders of magnitude higher water permeation compared to that of traditional membranes. Few layers MOF membranes show 1 order of magnitude higher water flux compared to that of single-layer nanoporous graphene or molybdenum disulfide (MoS) without the requirement of drilling pores. The excellent performance of 2D MOF membranes is supported by water permeation calculations, water density/velocity profiles at the pore, and the water interfacial diffusion near the pore. Water desalination performance of MOF offers a potential solution for energy-efficient water desalination.
提供新鲜的饮用水是当今世界面临的一项重大挑战。纳米材料的发展为利用节能型纳米多孔材料进行海水淡化创造了可能性。在这项工作中，我们证明了超薄导电金属有机框架（MOF）能够有效排斥离子，同时实现高水通量。通过分子动力学模拟，我们发现二维（2D）多层MOF具有完美的离子排斥率。与传统膜相比，二维MOF的天然多孔结构使水渗透量显著提高3至6个数量级。与单层纳米多孔石墨烯或二硫化钼（MoS）相比，少层MOF膜的水通量高出1个数量级，且无需钻孔。二维MOF膜的优异性能得到了水渗透计算、孔隙处的水密度/速度分布以及孔隙附近的水界面扩散的支持。MOF的海水淡化性能为节能海水淡化提供了一种潜在的解决方案。
