Abstract

The presence of azithromycin, a macrolide antibiotic, in aquatic environments poses a significant environmental concern due to its potential impacts on aquatic ecosystems and human health. This study proposes an eco-friendly, highly efficient and robust photodegradation process for the removal of azithromycin from aqueous samples. The photodegradation experiments were conducted under basic conditions (optimal pH approximate to 11) using a 300 W Xe lamp (lambda > 350 nm) with UV blocking filter. The nanocomposite displayed a nanorod-shaped sponge-like structure cobalt oxide/graphitic carbon nitride composite as the photocatalyst. The nanocomposite was synthesized and characterized using XRD, SEM, EDS, TEM, BET, and zeta potential analysis. The results demonstrated that approximately 97% of azithromycin was degraded within 60 min under visible light irradiation in the presence of the Co3O4/g-C3N4 photocatalyst. The photodegradation kinetics followed a first-order model, with a rate constant of 0.0536 1/min. BET analysis revealed that the Co3O4/g-C3N4 photocatalyst exhibits a mesoporous structure, contributing to a high specific surface area primarily attributed to the g-C3N4 component. The mechanistic study indicated that Co3O4 facilitated the generation of hydroxyl radicals ((OH)-O-center dot), while g-C3N4 promotes the formation of superoxide radicals (O-center dot(2)-), thereby enhancing the overall radical generation ((OH)-O-center dot and O-center dot(2)-) within the Co3O4/g-C3N4 nanocomposite. These properties significantly improve the photocatalytic efficiency of the Co3O4/g-C3N4 nanocomposite in azithromycin degradation.