Removal of per- and polyfluoroalkyl substances and nanoplastics from water using selected nanomaterial-based membranes: A review.

Nanomaterial-based membranes have emerged as promising candidates for advanced water purification because of their unique physicochemical properties and versatile functionalities. MXenes, MOFs, and GO were selected because they represent complementary membrane platforms: MXenes provide hydrophilic and conductive lamellar channels, MOFs offer tunable porosity and adsorption sites, and GO supplies oxygenated functional groups and two-dimensional transport pathways. MXene-based membranes exhibit strong hydrophilicity, tunable surface termination, and high conductivity, which facilitate the removal of persistent organic pollutants such as per- and polyfluoroalkyl substances (PFASs) and emerging contaminants such as nanoplastics (NPs) through electrostatic interaction and size-exclusion. Metal-organic framework (MOF)-based membranes, with their high porosity and structural diversity, further enhance water flux and selective separation, whereas graphene oxide (GO)-based membranes improve antifouling resistance and enable hydrogen bonding and electrostatic interactions. Hybrid and composite structures that integrate MXenes, MOFs, and GO achieve synergistic performances of high flux, retention efficiency, and fouling resistance. However, the economic feasibility of such hybrid membranes depends on reducing nanomaterial loading, simplifying synthesis routes, minimizing solvent and energy consumption, and ensuring scalable fabrication without sacrificing separation performance. Despite these advances, significant challenges remain in terms of scalability, long-term stability, and performance under multi-pollutant conditions in which salts, heavy metals, and natural organic matter often coexist and interfere with membrane separation. Addressing these issues requires multifunctional designs, greener fabrication strategies, and integration with catalytic or electrochemical processes to ensure sustainable and durable operation. Accordingly, this review provides a comprehensive overview of recent progress in MXene-, MOF-, and GO-based membranes for PFAS and NP removal, highlighting separation mechanisms, performance outcomes, and future directions, with the central message that practical implementation requires simultaneous consideration of removal efficiency, flux stability, material durability, scalability, and performance under realistic multi-pollutant water conditions.