Enhanced antifouling performance of polyvinyl alcohol membranes via magnetite-graphene oxide nanocomposite modification

Addressing the persistent trade-off between permeability, selectivity, and fouling resistance remains a central challenge in advancing polymeric membranes for sustainable wastewater treatment. Here, we present a high-performance mixed- matrix membrane (MMM) platform that leverages interfacial coordination chemistry between binary magnetite ( Fe 3 O 4 ) and graphene oxide (GO) nanostructures to reconstruct the internal microarchitecture of a hydrophilic polyvinyl alcohol (PVA) matrix. By co-assembling Fe 2 + / Fe 3 + metallic centres with oxygenated GO domains, the nanohybrid suppresses nanoscale agglomeration and constructs continuous low-tortuosity fluid transport channels. Systematic characterisation (FTIR, 1 H NMR, SEM–EDX, XRD, and Zeta potential) confirmed enhanced interfacial surface dynamics, tuned surface charge, and increased hydrophilicity. Compared to the pristine PVA control, which suffered from severe fouling (73.2% total fouling ratio; 26.8% flux recovery ratio (FRR)) and modest performance (57.2 L ⋅ m − 2 ⋅ h − 1 pure water flux (PWF); 52.5% methylene blue (MB) rejection), the optimised 0.6 wt% Fe 3 O 4 / GO (PVA-F0.6/G0.6) membrane effectively overcomes conventional performance trade-offs. It achieved a high porosity of 73.6%, an elevated PWF of 85.1 L ⋅ m − 2 ⋅ h − 1 , and a 90.1% MB rejection efficiency, alongside exceptional antifouling durability marked by a 94.0% FRR and an ultra-low irreversible fouling resistance of just 6.0%. This coordinated nanohybrid design offers a robust, scalable strategy for engineering next-generation, antifouling polymeric membranes for advanced water purification.