Weifeng Li,†Yanmei Yang,†Jeffrey K. Weber,‡Gang Zhang,*,§and Ruhong Zhou*,†,‡,∥

Abstract

The deteriorating state of global fresh water resources represents one of the most serious challenges that scientists and policymakers currently face. Desalination technologies, which are designed to extract potable water from the planet’s bountiful stores of seawater, could serve to alleviate much of the stress that presently plagues fresh water supplies. In recent decades, desalination methods have improved via waterfiltering architectures based on nanoporous graphene filters and artificial membranes integrated with biological water channels. Here, we report the auspicious performance (in simulations) of an alternative nanoporous desalinationfilter constructed from a MoS2 nanosheet. In striking contrast to graphene-basedfilters, we find that the“open”and“closed”states of the MoS2 filter can be regulated by the introduction of mechanical strain, yielding a highly tunable nanopore interface. By applying lateral strain to the MoS2filter in our simulations, we see that the transition point between “open”and“closed” states occurs under tension that induces about 6% cross-sectional expansion in the membrane (6% strain); the open state of the MoS2 filter demonstrates high water transparency and a strong salt filtering capability even under 12% strain. Our results thus demonstrate the promise of a controllable nanoporous MoS2 desalinationfilter, wherein the morphology and size of the central nanopore can be precisely regulated by tensile strain. Thesefindings support the design and proliferation of tunable nanodevices forfiltration and other applications.

Zhou-ACS Nano 2016 MoS2 desalination.pdf