Effects of structural parameters on the desalination performance of a multilayer stacked graphene oxide membrane: insights from molecular dynamics simulation

Abstract

With the rapid development of nanotechnology, functionalized graphene membranes have shown great advantages, attracting increasing attention in recent years. However, the effects of different groups on the desalination performance of layered graphene membranes, as well as the transport and separation mechanisms of water molecules and ions within two-dimensional nanochannels, remain insufficiently understood. In this study, molecular dynamics simulations are employed to investigate the influence of multiple factors on seawater desalination performance, focusing on transport behavior and intermolecular interactions, to elucidate the structure–performance relationship between the membrane architecture and separation efficiency. Our findings indicate that the desalination performance of a multilayer stacked graphene oxide membrane (MGOM) is affected by key structural parameters, including interlayer spacing (H), offset (O), and slit width (dG). Optimal performance is achieved when H = 0.8 nm, dG = 1.1 nm, and O = 1.26 nm. Interestingly, the rejection rate of Na⁺ is slightly lower than that of Cl⁻, mainly due to the differences in the interaction between different ions and functional groups in the sheets and the hydration radius.