Highly efficient photocatalytic degradation of ciprofloxacin under simulated sunlight using g-C3N4/CeO2/Fe3O4 heterogeneous composite

Abstract

The presence of antibiotic residues in water bodies has become a serious environmental concern due to their persistence and ability to cause bacterial resistance. Traditional water treatment methods are often ineffective at completely degrading these pollutants, highlighting the need to investigate more effective remediation methods. In this study, the photocatalytic degradation of ciprofloxacin, a widely used fluoroquinolone antibiotic, was investigated using a novel heterogeneous composite of g-C₃N₄, CeO₂, and Fe₃O₄ under simulated sunlight irradiation. The composite was synthesized and thoroughly characterized using SEM, EDX, TEM, XRD, BET, PL, RIS, and FT-IR analysis to validate its structural and morphological properties. The effects of key operational parameters, including composite concentration, CeO₂ weight percentage, pH, and H₂O₂ concentration, on photocatalytic performance were investigated. Among all the synthesized composites, the sample with a 0.75:0.75:1 wt ratio (designated as F0.75C0.75 G) displayed the highest photocatalytic activity, achieving a ciprofloxacin removal efficiency of 97.5 % within 180 min. The ternary composite outperformed individual components (g-C₃N₄, CeO₂) and binary composites (g-C₃N₄/CeO₂) due to enhanced charge separation and extended light absorption. In addition, recyclability tests confirmed that the composite maintained high degradation efficiency even after five cycles, highlighting its stability. The treated solution demonstrated excellent biocompatibility, as evidenced by improved lentil seed germination. These findings presents a cost-effective and sustainable approach for the degradation of pharmaceutical pollutants in water resources, offering a promising solution for environmental remediation.