Résumé
Stacking two-dimensional (2D) nanosheets into laminar membranes to create nanochannels has attracted widespread attention at fundamental and practical levels for separation technology. Constructing space-tunable and long-term stable sub-nanometer channels provide original systems for nanofluidic investigations and accurate molecular sieving. Here, we report a scalable strategy for the preparation of non-swelling covalently functionalized molybdenum disulfide (MoS2) membranes with tunable cohesion energy and interlayer space from 3.5 to 2 7.7 Å, depending on the nature of the functional groups attached to the MoS2 nanosheets. We evaluated the relationship between the capillary width, the surface chemistry, the stacking disorder and the sieving behaviors of the membranes in forwards osmosis (FO). By combining experimental investigations and numerical simulations, we identified that the functionalization with aryl groups induces the formation of a capillary width of 7.1 Å and interlayer stiffness as low as 5.6 eV Å-2 , leading to controlled stacking defects. We report the fabrication of membranes up to 45 cm 2 , which demonstrate a salt rejection as high as 94.2% for a continuous operating time of 7 days. Our work presents a desalination strategy in FO with a specific energy consumption (SEC) of 4 × 10-3 kWh m-3 , which compares favorably with commercial FO membranes.