Rapid and scalable fabrication of UiO-66-NH2 membrane for ultra-high-flux oil–water separation without any compromising rejection coefficient

Energy-efficient membrane technologies have attracted significant attention in oil–water separation, yet the persistent permeability-selectivity trade-off remains a critical challenge. While traditional Zr-based MOF membranes demonstrate exceptional stability for such applications, their practical implementation is hindered by the high energy barrier of Zr-O bond formation, necessitating harsh synthetic conditions (prolonged durations and toxic organic solvents) that impede large-scale production. This study presents a breakthrough in rapid, scalable membrane fabrication through an innovative solvent impregnation strategy, successfully developing UiO-66-NH₂@stainless-steel mesh (UiO-66-NH₂@SSM) membranes for ultrahigh-flux oil–water emulsion separation without compromising rejection efficiency. By utilizing ethanol as an eco-friendly reaction medium, we achieved in-situ growth of UiO-66-NH₂ on SSM substrates within merely 3 h − an 87.5 % reduction in synthesis time compared to conventional solvothermal methods (24 h). The optimized membrane exhibits record-breaking permeation fluxes up to 11.0 × 10⁴ L m⁻² h⁻¹ while maintaining exceptional separation efficiencies (>99.9 %) for various oil emulsions (chloroform, petroleum ether, and n-hexane). This flux performance surpasses the state-of-the-art UiO-66-NH₂ membranes by 28.9 %, representing unprecedented advancement in the field. The exceptional performance originates from a hierarchical micro-nano architecture featuring UiO-66-NH₂ nanoclusters on SSM, which synergistically enhances surface hydrophilicity and creates optimized water transport channels. Furthermore, the membrane demonstrates remarkable durability and chemical resilience against extreme pH conditions and high-salinity environments. Notably, the fabrication process maintains consistent performance metrics during scale-up, highlighting its potential for industrial implementation. This work not only provides an efficient solution for separating submicron oil droplets in emulsions but also overcomes the fundamental permeability-selectivity trade-off effect in membrane-based separation technologies.