Photocatalytic Degradation of Fluoroquinolones Antibiotics in River Water Over BiOBr Irradiated by Direct Sunlight

ABSTRACT The occurrence of antibiotics in river waters has become an increasing environmental concern due to their role in promoting bacterial resistance and inducing toxic effects in aquatic organisms. Among these contaminants, fluoroquinolones such as ciprofloxacin (CIP) and moxifloxacin (MOX) are widely used in clinical practice and show high environmental persistence. This study investigated the degradation of CIP and MOX in river water via heterogeneous photocatalysis using bismuth oxybromide (BiOBr) under direct solar and polychromatic irradiation. The structural properties of BiOBr were confirmed by x‐ray diffraction (XRD), Raman spectroscopy, and complementary techniques, writing down well‐defined crystalline organization. Optical properties and photocatalytic performance were evaluated by UV–vis spectroscopy. Photocatalytic assays showed high efficiency, achieving photodegradation rates of 95% for MOX and 93% for CIP within 120 min under natural sunlight in real water matrices. Total organic carbon (TOC) analysis revealed mineralization rates of 77% (MOX) and 74% (CIP). These findings show that BiOBr exhibits significant photocatalytic activity under environmentally relevant conditions, highlighting its potential as a sustainable technology for wastewater treatment and mitigation of antibiotic contamination in aquatic systems.