Construction\nof Asymmetric Filler Density Mixed-Matrix\nMOF Membranes via Liquid-Phase Ion Activation for Advanced Oxidation\nProcesses

Mixed-matrix membrane (MMM) reactors incorporating metal–organic\nframework (MOF) fillers have significant applications in fields such\nas separation, catalysis, and chiral resolution. However, the traditional\nmethod of directly mixing MOF fillers with polymers results in a symmetric\nstructure where most of the MOF fillers are uniformly distributed\nacross the membrane reactor’s cross-section. During usage,\nthis leads to a pronounced trade-off between flux and efficiency and\nthe waste of the MOF, as the rich pore characteristics and active\nsites of MOFs are not fully utilized. In this study, we propose a\nliquid-phase ion activation strategy that enables the in situ formation\nof a uniform and densely packed MOF shell layer on the membrane surface\nduring the phase inversion process of MMM fabrication. This asymmetric\ndensity distribution of the MOF-based MMM reactor selectively induces\nthe generation of considerable nonradical <sup>1</sup>O<sub>2</sub> in the peroxomonosulfate (PMS) system, demonstrating superior catalytic\ndegradation performance against antibiotics like TC and dye molecules\n(with a flux of 1880 L m<sup>–2</sup> h<sup>–1</sup> and a <i>K</i><sub>app</sub> value of 648 min<sup>–1</sup>), as well as outstanding cycling stability and environmental tolerance.\nThis discovery sheds light on the design and engineering of composite\nmembrane materials and applications for advanced oxidation processes\nin water purification.