Few-layers MoS2 nanosheets modified thin film composite nanofiltration membranes with improved separation performance

Two-dimensional (2D) molybdenum disulfide (MoS2) nanosheets materials with excellent properties provide a new possibility and approach for designing nanofiltration (NF) membranes with overcoming the “trade-off” phenomenon of permselectivity. Few-layers of 2D MoS2 were synthesized by a facile solvent-assisted ultrasonic exfoliation method. A novel nanocomposite NF membrane was fabricated through interfacial polymerization by addition of the as-prepared MoS2 nanosheets into the organic phase at different concentrations. The characterization of field-emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM) confirmed that MoS2 nanosheets were successfully embedded in the membranes. As a result, the hydrophilicity, electronegativity and cross-linking degree of the membranes were significantly enhanced. The membrane achieved its best performance at a MoS2 concentration of 0.010 wt/v% with about 2.3 times increment in water permeability without sacrificing salt rejection compared to the control membrane. Moreover, the modified membrane exhibited higher stability over a long-term test. This provides new thinking and guidance for the industrial preparation of NF with excellent separation performance.