Oxygen vacancy and nanoconfinement synergize in CoFe-LDH catalytic membranes for efficient peroxymonosulfate activation and water purification

Efficient peroxymonosulfate (PMS)-based degradation of refractory antibiotics is still hindered by slow mass transfer and insufficient utilization of catalytic sites in heterogeneous systems. Although layered double hydroxide (LDH) membranes and oxygen vacancy (Ov) engineering have been explored separately, how Ov-mediated PMS activation works together with nanoconfined transport remains unclear. Herein, we report an Ov-engineered CoFe-LDH catalytic membrane (LDH-8 MEM) for continuous-flow PMS activation and antibiotic degradation. The LDH-8 MEM/PMS system achieved rapid ofloxacin removal with high water permeance and an apparent pseudo-first-order rate constant of 65.09 s -1 under continuous-flow operation. Density functional theory (DFT) calculations indicate that Ov facilitates PMS adsorption and initial O-O bond activation. Electron paramagnetic resonance (EPR) and quenching experiments suggest that 1 O 2 is more involved in OFN oxidation under the tested conditions. Gaussian/Multiwfn analyses and molecular dynamics (MD) simulations suggest that PMS-pollutant hydrogen bonding and nanoconfined channels may favor local reactant enrichment and interfacial contact. This study provides insight into the coupled role of defect sites and confined membrane channels in PMS activation, offering guidance for designing efficient catalytic membranes for water purification.