Integrated adsorption and photocatalytic degradation of ciprofloxacin using a Z-scheme g-C3N5/LaFeO3-embedded mixed matrix membrane: Performance and toxicity assessment

Abstract

Persistent organic pollutants like ciprofloxacin (CIP) resist conventional treatment, and traditional powder photocatalysts suffer from secondary leaching, particle agglomeration, and poor recovery. Addressing this critical gap, a novel Z -scheme g-C3N5/LaFeO3 (CNLF) nanohybrids was immobilized within a porous polyvinylidene fluoride/polyvinyl alcohol matrix to create an integrated “capture-and-degrade” mixed matrix membrane (MMM). The optimized CNLF-3/MMM exhibited enhanced hydrophilicity, structural stability, and a 63.5% ( k 2, ads = 0.0128 mg g−1 min−1) CIP adsorption efficiency driven by electrostatic and π-π interactions. Under visible light, the integrated CNLF-3/MMM delivered 94.8% of CIP degradation ( k 6,deg = 0.0384 min−1) within 60 min, alongside a total organic carbon mineralization rate of 43.31%. In addition, the CNLF-3/MMM exhibited superior antifouling performance and high flux recovery against complex foulants. Mechanistic investigations confirmed a dual-mechanism pathway involving Z -scheme charge transfer and a photo-Fenton process facilitated by Fe2+/Fe3+ cycling and oxygen vacancies in LaFeO3. Finally, computational toxicity assessments verified that the resulting transformation by-products pose significantly lower ecological risks than the parent CIP molecule. Ultimately, the developed MMM system offers a scalable, highly stable, and environmentally safe platform for advanced wastewater remediation. © 2026 Elsevier B.V.