Highly permeable and ultra-selective polyamide nanofiltration membrane with nanoconfined LDH-embedded composite structure for enhanced water purification

Reactive nanofiltration (NF) systems that couple polyamide NF (PA-NF) with advanced oxidation processes reportedly offer a promising route for simultaneous degradation of emerging organic pollutants and desalination. However, their performance is constrained by limited catalytic activity, mass-transfer barriers, and trade-off between permeability–selectivity. Here, we develop a high-performance catalytic PA-NF membrane by introducing a layered double hydroxide (LDH) interlayer with the aim on creation of nanoconfined spaces within the internal membrane structure for enhancement in oxidant activation and mass transport. It was found that the interfacial polymerization by restricting amine diffusion can effectively be regulated, yielding a thin, defect-free PA layer enabling fast water transport and precise ion selectivity. The nanoconfinement with peroxymonosulfate markedly boosts oxidant delivery and electron-transfer efficiency, accelerating radical generation. Hence, the catalytic LDH-interlayered PA-NF membrane exhibited high water permeance (34.8 L/(m 2 ·h·bar)) and excellent ion selectivity, while simultaneously achieving nearly 100% atrazine degradation with a rate constant of 0.034 min −1 , far outperforming non-confined systems, even under natural organic matter and ionic interference. This work would provide a better solution for design of cost-effective materials for next-generation reactive NF technologies and sustainable water and wastewater treatment.