Two-dimensional WS2 membranes constructed on different substrates for efficient dye desalination

Two-dimensional (2D) membranes have been widely used in water purification due to their excellent separation performance. Herein, 2D WS2 membranes were constructed on polyamide (PA) and anodic aluminum oxide (AAO) substrates for efficient dye desalination. Different with previous reports, we discovered that the dry PA supported WS2 (WS2/PA) membrane still permitted water to pass through, relating to the rougher surface of PA than that of AAO, which formed more larger interlayer spacing of 1.18 nm in the WS2/PA membrane. Moreover, the WS2/PA membrane had a higher water permeance and a lower salt rejection compared with that of AAO supported WS2 (WS2/AAO) membrane with similar dye rejection, and a water permeance of 597 L/m(2).h.bar was achieved through a 250 nm-thick WS2/PA membrane with a Rose Bengal (RosB) rejection of 98.5% and a NaCl rejection of 0.3%. And this water permeance is approximately one order of magnitude higher than that through reduced graphene oxide membranes in a solvation state (S-rGO) with similar dye and salt rejections, indicating their promising prospect in the application of dye desalination.