Su Yuyu, Liu Dan, Yang Guoliang, Han Qi, Qian Yijun, Liu Yuchen, Wang Lifeng, Razal Joselito M, Lei Weiwei
Institute for Frontier Materials, Deakin University, Waurn Ponds Campus, Geelong, Victoria 3220, Australia.
School of Science, College of Science Engineering and Health, RMIT University, Melbourne, Victoria 3000, Australia.
ACS Appl Mater Interfaces. 2020 Oct 7;12(40):45453-45459. doi: 10.1021/acsami.0c10653. Epub 2020 Sep 28.
Two-dimensional (2D) transition metal dichalcogenide membranes have entered the spotlight for nanofiltration application owing to the novel mass transport properties in nanochannels. However, further improving the water permeability with high molecular separation rate simultaneously is challenging. In this work, to achieve ultrafast molecule separation, MoS and WS nanosheets with ultrasmall lateral size (<100 nm) are fabricated by sucrose-assisted mechanochemical exfoliation. Ultrasmall nanosheets in the membranes cut down average length of water-transporting paths and create more nanochannels and nanocapillaries for water molecules to pass through membranes. The water flux of these kinds of MoS and WS membranes are significantly enhanced to 918 and 828 L/m h bar, respectively, which is four and two times higher than those of previously reported MoS and WS membranes with larger lateral size nanosheets. In addition, MoS and WS membranes display excellent rejection performance for rhodamine B and Evans blue with a high rejection rate (∼99%). This study provides a promising method to improve the performance of 2D laminar membranes for nanofiltration application by using ultrasmall 2D nanosheets.
二维（2D）过渡金属二硫属化物膜因其在纳米通道中具有新颖的传质特性，在纳滤应用方面已备受关注。然而，要同时进一步提高水渗透性和高分子分离率仍具有挑战性。在这项工作中，为了实现超快速分子分离，通过蔗糖辅助机械化学剥离制备了横向尺寸超小（<100 nm）的MoS和WS纳米片。膜中的超小纳米片缩短了水传输路径的平均长度，并为水分子穿过膜创造了更多的纳米通道和纳米毛细管。这类MoS和WS膜的水通量分别显著提高到918和828 L/m h bar，分别是先前报道的具有较大横向尺寸纳米片的MoS和WS膜的四倍和两倍。此外，MoS和WS膜对罗丹明B和伊文思蓝表现出优异的截留性能，截留率很高（约99%）。本研究提供了一种有前景的方法，即通过使用超小二维纳米片来提高二维层状膜在纳滤应用中的性能。
