Surface-Charge-Regulated MoS2 Membrane for Induced Agglomeration and Efficient Removal of Nanopollutants

Conventional membranes for nanopollutant removal are constrained by the permeability-selectivity trade-off inherent in size-exclusion mechanisms. Here, we report a surface-charge-regulated MoS2 membrane engineered by anchoring copper nanoparticles and quaternary ammonium groups onto MoS2 nanosheets. This functionalization creates a porous 3D architecture while tuning the surface charge density to induce the agglomeration of oppositely charged nanopollutants (e.g., nanoplastics and metal oxides), effectively increasing their size for enhanced rejection. The optimized copper-functionalized membrane (M-I-Cu0.63) achieves an exceptional water permeance of 804.3 ± 35.4 L/(m2·h·bar) with 99.68% rejection of positively charged pollutants. Conversely, the cetyltrimethylammonium bromide-functionalized counterpart (M-I-C2.4) provides a water permeance of 512.9 ± 21.1 L/(m2·h·bar) and 99.43% rejection for negatively charged species. This charge-directed strategy overcomes intrinsic filtration limits, offering a promising route for high-efficiency, next-generation water purification.