Two-Dimensional MoS ₂ /MXene Heterostructure Membranes for Selective Organic Solvent Nanofiltration: A Molecular Dynamics Investigation

Organic solvent nanofiltration (OSN) is a key technology for solvent recovery and energy reutilization, offering notable advantages in separation efficiency and energy reduction, and has thus gained significant attention in membrane research. Developing OSN membranes that combine high flux with high selectivity remains a central challenge. Molybdenum disulfide (MoS2) and transition metal carbides/nitrides (MXene), as chemically stable two-dimensional materials, show considerable potential for building high-performance separation membranes. In this study, MoS2/Ti3C2O2 hybrid membranes with varied interlayer spacings were modeled, and their nanofiltration performance toward five organic solvents (n-hexane, methanol, ethanol, acetonitrile, acetone) and the model solute paracetamol (PRM) was systematically studied using molecular dynamics simulations. Results show that solvent flux is governed collectively by molecular size, viscosity, solvent–membrane interactions, and interlayer spacing. As spacing increases, flux correlates inversely with viscosity. Solute rejection is largely controlled by solvent–solute interactions and differs markedly across solvents. Compared to pure MoS2 and pure Ti3C2O2 membranes, the hybrid membrane shows superior flux in most solvents (except n-hexane), while its rejection lies between those of the two pure membranes, except in n-hexane and ethanol systems. This study clarifies the molecular-level transport and rejection mechanisms in MoS2/Ti3C2O2 hybrid membranes, offering theoretical guidance for the rational design of high-performance OSN membranes.