Intensify Mass Transfer and Molecular Oxygen Activation by Defect-Bridged Asymmetric Catalytic Sites Toward Efficient Membrane-Based Nanoconfined Catalysis

Efficient spontaneous molecular oxygen (O₂) activation is expected in advanced oxidation processes. However, it remains a great challenge to promote the reactants adsorption and accelerate the interfacial electron transfer to boost the activation kinetic of O₂. Herein, defect-rich N-doped reduced graphene oxide/CoFe₂O₄ (NGCF-O_V) membrane containing asymmetric Co-O_V-Fe sites is prepared for O₂ activation. The intrinsic catalytic activity is that the asymmetric Co-O_V-Fe sites regulate the O─O bond length, promoting more and faster electron transfer to O₂ for selectively producing ¹O₂. Meanwhile, the adjacent graphitic N sites help confine organics to the surface and thus greatly shorten the reaction distance of ¹O₂ and improve its utilization efficiency. The NGCF-O_V membrane demonstrates complete degradation of bisphenol A within a retention time of 86 ms, achieving a k-value of 0.047 ms⁻¹, which exceeds the performance of most Fenton-like systems. This work provides new horizons for designing an efficient and stable catalytic membrane, enriching the domain of advanced wastewater treatment strategies.