Development of a carbon coated LaCuFeO₃ core-shell catalyst for simultaneous degradation of fluoroquinolone organic pollutants in wastewater: enhanced catalysis via nanospace confinement

BACKGROUND: Fluoroquinolone antibiotics (FQs) such as ciprofloxacin (CIP) and ofloxacin (OFL) are persistent contaminants in wastewater, posing significant environmental and health risks. Their simultaneous removal remains challenging. Advanced oxidation processes based on peroxydisulfate (PDS) activation offer a promising solution but often require efficient and stable catalysts. This study aims to develop a novel core-shell carbon-coated perovskite catalyst for the simultaneous and efficient degradation of these pollutants. 

RESULTS: A core-shell LaCuFeO₃@C catalyst was successfully synthesized via a sol–gel method using citric acid/EDTA as an integrated carbon source, followed by calcination and acid etching. The LaCuFeO₃@C/PDS system achieved 100% degradation of both CIP and OFL within 30 min using only 0.5 mM PDS and 0.2 g/L catalyst. The catalyst demonstrated excellent stability, retaining high removal efficiencies for CIP (91.9%) and OFL (93.4%) after 4 consecutive cycles. Furthermore, the carbon coating conferred exceptional resistance to high concentrations of interfering anions (100 g/L of Cl⁻ and SO₄²⁻). The core-shell structure, confirmed by TEM-EDS analysis, provides nano-cavities that enhance reactant diffusion, enrich pollutants via adsorption, and facilitate efficient PDS activation. 

CONCLUSION: The LaCuFeO₃@C catalyst presents an efficient, robust, and sustainable strategy for the simultaneous removal of complex fluoroquinolone pollutants in wastewater, even under challenging high-salinity conditions. Its superior performance and stability are attributed to the synergistic adsorption-enrichment-activation mechanism within the unique core-shell architecture.