Abstract
Biological aquaporins possessing unimolecular directional pores provide exceptional transport performances for water translocation. Inspired by biological counterparts, artificial water channels (AWCs) could be used to overcome the permeability/selectivity trade-off of traditional desalination membranes. Here, we demonstrate that the directional incorporation of AWCs in composite MXene membranes, provided the first example of biomimetic two-dimensional (2D) membranes, enabling Å-scale separations with intrinsic water-to-salt permselectivity on the operational reverse osmosis (RO) desalination conditions. Compared with the pristine MXene membrane, the synergy of size sieving and electrostatic repulsion of the AWCs-MXene membranes provided doubled permeance (4–6 L m−2 h−1 bar−1), and salt rejection (87% (NaCl), 93% (MgCl2), 97% (Na2SO4 and MgSO4). Additionally, the AWCs-MXene membranes showed significantly enhanced anti-swelling and anti-fouling abilities, demonstrating high stability with almost no performance decline after 7-day filtration. Thus, the rational design of 2D AWCs-MXene membranes combined the adjustable interlayer spacing with adaptive AWCs pathways, dedicated to selective water transport under molecular control.