Stacking engineering of multilayer WS2/GO hybrid membranes for enhanced desalination performance: A molecular dynamics study

The rapid development of two-dimensional (2D) hybrid membranes has provided new research avenues for membrane-based seawater desalination technologies. In this study, four types of three-layer stacked hybrid membrane structures were constructed by combining hydrophilic graphene oxide (GO) membranes with hydrophobic tungsten disulfide (WS₂) membranes, and the desalination mechanisms of these hybrid membranes were thoroughly investigated using molecular dynamics (MD) simulations. The results demonstrate that the configuration of edge atoms in the WS₂ membrane significantly influences its desalination performance: The W–S membrane exhibits the highest water permeance, while the S–S membrane shows the highest ion rejection rate. Based on these findings, four distinct hybrid membrane stacking configurations were designed. The simulation results reveal that the GO-S-GO configuration with an interlayer spacing of 9 Å demonstrates optimal overall performance, achieving a water permeance of 21.57 × 10² L/m²/h/bar with ion rejection rates of 100 % for Na⁺ and 98.1 % for Cl⁻. Furthermore, by reducing the oxidation degree of GO and optimizing the interlayer spacing, the water permeance can be enhanced without compromising the 100 % ion rejection rate. This study elucidates the influence of surface characteristics of WS₂/GO hybrid membranes on water permeation and ion transmembrane transport, providing critical theoretical guidance for the development of high-efficiency, energy-saving novel desalination membrane materials.