Ultrafast Molecule Separation through Layered WS₂ Nanosheet Membranes

Abstract

Two-dimensional layered materials have joined in the family of size-selective separation membranes recently. Here, chemically exfoliated tungsten disulfide (WS2) nanosheets are assembled into lamellar thin films and explored as an ultrafast separation membrane for small molecules with size of about 3 nm. Layered WS2 membranes exhibit 5- and 2-fold enhancement in water permeance of graphene oxide membranes and MoS2 laminar membranes with similar rejection, respectively. To further increase the water permeance, ultrathin nanostrands are used as templates to generate more fluidic channel networks in the WS2 membrane. The water permeation behavior and separation performance in the pressure loading-unloading process reveal that the channels created by the ultrathin nanostrands are cracked under high pressure and result in a further 2-fold increase of the flux without significantly degrading the rejection for 3 nm molecules. This is supported by finite-element-based mechanical simulation. These layered WS2 membranes demonstrate up to 2 orders of magnitude higher separation performance than that of commercial membranes with similar rejections and hold the promising potential for water purification.

Design and function of biomimetic multilayer water purification membranes

“…Remarkably, fluxes of 0.3-μm-thick SNF/HAP membranes are up to 8355 liter hour −1 m −2 bar −1 , more than 1000 times higher than those of commercial filtration membranes ( 41 – 43 ) and more than 4 times higher than those of most advanced, recently reported ultrathin membranes with similar thicknesses (Fig. 4E) ( 4 , 5 , 9 – 11 , 18 , 20 , 21 ). In addition, the flux of the SNF/HAP membranes is stable in a 24-hour filtration assessment (Fig.…”

“…A more detailed discussion about dye separation and adsorption performance of SNF/HAP membranes can be found in section S9. Figure 4H compares the separation efficiencies of SNF/HAP membranes for 5-nm gold nanoparticles with other water purification membranes reported in the literature ( 4 – 6 , 10 , 11 , 14 , 15 , 17 , 21 ). The SNF/HAP membranes extend the “instep” pattern of the reported thickness versus flux relationship and exhibit a more effective integration of thickness, flux, and separation performance.…”

“…For flux assessments, we followed the method used for other ultrathin membranes ( 4 – 6 , 10 , 11 , 14 , 15 , 17 , 21 ). Typically, water or model compound solutions were filtered through the as-prepared membranes, which stand on a porous support membrane.…”

A CNT@MoSe2hybrid catalyst for efficient and stable hydrogen evolution

“…[7][8][9] Layered transition metal dichalcogenides (LTMD), whose crystal structures are composed of covalently bonded X-M-X (M = Mo, W, etc. ; X = S, Se, Te) layers by van der Waals forces like graphite, 10,11 have received much attention in energy conversion and storage fields due to their tunable band structure and intrinsic electrochemical properties. [12][13][14][15][16][17] MoS 2 and WS 2 based materials have been reported as highperformance HER catalysts and lithium-ion battery anodes in terms of remarkable catalytic activity and high capacity.…”

Research Progress in Application of 2D Materials in Liquid-Phase Lubrication System

“…Thus, 2D materials are selected as high-performance and environmentally friendly lubricants [45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60]. …”