Precise ångström controlling the interlayer channel of MoS2 membranes by cation intercalation.

MoS 2 nanosheets have been used as building block candidates for assembling two dimensional (2D) laminates. However, the use of MoS 2 membranes remains to be severely imposed by the narrow interlayer width of ~3 Å. In this work, we proposed a feasible and efficient approach to enlarge the interlayer distance of MoS 2 membranes using cations (K+, Na+, Li+ or Mg2+) intercalation. The resulting membranes show significant increases in interlayer widths, which attain 6.25, 6.63, 7.25, and 8.48 Å for K+, Na+, Li+ and Mg2+ regulation respectively. Moreover, the 2D galleries' regularity in cations inserting MoS 2 membranes is well inherited from that of the original MoS 2 membrane. The water purification performances further validate the cations intercalation manipulation. In the nanofiltration mode, cations interlacation enables the water permeances of MoS 2 membranes to improve 2–3 times without sacrificing dye rejections. In the forward osmosis mode, the water permeances of cations intercalating MoS 2 membranes almost improve an order of magnitude (24.4× 10−3 - 36.4 × 10−3 L m−2 h−1 bar−1) in comparison with the pristine MoS 2 membrane (3.4 × 10−3 L m−2 h−1 bar−1), while retaining the comparable NaCl rejections. This approach of broadening 2D channels paves a way to the design and regulation of 2D membranes for achieving extending applications. Image 1 • The interlayer distance of MoS 2 membranes was enlarged using cation intercalation. • The interlayer width of Mg2+ regulating MoS 2 membranes reaches 8.48 Å. • Cation intercalation has no impact on the interlayer regularity of MoS 2 membranes. • The permeances of cation regulating MoS 2 membranes improve an order of magnitude. [ABSTRACT FROM AUTHOR]