Highly efficient and stable Photo-Fenton-Like catalytic membrane based on Yolk-Shell MOF-on-MOF Nanostructures for Broad-Spectrum antibiotic removal

Antibiotic wastewater, characterized by its complex compositional diversity, structurally refractory compounds, and poorly understood environmental impacts, has emerged as a critical target for emerging contaminants remediation. To address these challenges of low catalytic activity and poor recyclability in antibiotic wastewater treatment, we developed a yolk-shell MOF-on-MOF catalyst (NH₂-MIL-88B-PVP@CoZn-ZIF, O-YSNs). Subsequently, the catalyst was modified with tannic acid (TA) to enhance dispersibility, and immobilized onto a polyvinylidene fluoride (PVDF) membrane via crosslinking using polyvinyl alcohol (PVA) and glutaraldehyde (GA). The system synergistically integrated visible-light irradiation with peroxymonosulfate (PMS) activation for efficient antibiotic degradation. Experimental results demonstrated that the catalytic membrane achieved removal efficiencies of 98.45 %, 87.60 %, 98.65 %, and 94.30% for tetracycline hydrochloride, ciprofloxacin, oxytetracycline, and ceftriaxone sodium, respectively, within 30 min. Moreover, the stable structure of the crosslinking layer effectively minimized the loss of the catalyst, and the removal rate of tetracycline hydrochloride still reached over 90 % after six consecutive cycles. Radical scavenging experiments and electron paramagnetic resonance (EPR) analysis revealed the synergistic mechanism of multiple reactive oxygen species (O₂^•−, ^•OH, SO₄^•−, and ¹O₂) and holes (h⁺) during the degradation process. This work establishes a novel paradigm for developing catalytic membranes that simultaneously achieve high reactivity and operational stability, offering substantial potential for antibiotic wastewater remediation.