Study on the Performance and Efficiency of MgO/CuFeO₂ Composite Catalyst in Degradation of Organic Pollutants

With the acceleration of industrialization and increasing human activities, antibiotic pollutants enter aquatic environments through various pathways and pose serious threats to ecological safety and human health. Ofloxacin (OFX), a typical fluoroquinolone antibiotic, is persistent in water media owing to its high chemical stability and poor biodegradability. In this study, MgO/CuFeO₂-based Fenton-type composite catalysts were prepared to investigate their efficiency in removing OFX from water. Among the as-prepared materials, MgO/CuFeO₂-20 wt% exhibited the optimum catalytic activity: under the conditions of 20 mg L^-1 initial OFX concentration, 0.5 g L^-1 catalyst dosage and 20 mM H₂O₂ at natural pH, it achieved approximately 95% ofloxacin removal within 120 min, with a pseudo-first-order kinetic rate constant k₁ of 0.0461 min^-1. Benefiting from MgO modification, the catalyst maintained high degradation efficiency over a broad pH range of 5-9 and retained satisfactory catalytic performance after five consecutive cyclic runs with only minor activity decay. Characterizations including XRD, SEM-TEM, XPS, BET, LSV-EIS and ESR-DMPO verified that the construction of tight MgO-CuFeO₂ heterointerfaces accelerated interfacial electron transfer and promoted the regeneration of Cu⁺/Cu²⁺ and Fe²⁺/Fe³⁺ redox couples. Hydroxyl radicals (·OH) were identified as the dominant reactive oxygen species for pollutant oxidation. This work provides a facile modification strategy to alleviate particle aggregation and metal-ion leaching drawbacks of bare CuFeO₂, offering experimental support for designing high-efficiency delafossite-based heterogeneous Fenton-like catalysts for antibiotic-containing wastewater remediation.