Visible-light-assisted decontamination of sertraline in water using a Co₃O₄/g-C₃N₄ nanocomposite photocatalyst

A powerful, environmentally friendly, and effective photodegradation process for the decontamination of sertraline was developed and evaluated in this study. Specifically, the photocatalytic degradation of sertraline in aqueous samples under visible light irradiation was investigated using a nanonet-structured porous cobalt oxide/graphite carbon nitride (Co₃O₄/g-C₃N₄) composite as the photocatalyst. The Co₃O₄/g-C₃N₄ nanocomposite was synthesized and characterized by XRD, SEM, TEM, EDS, BET, and zeta-potential analyses. The results showed that under visible light irradiation (Vis/Co₃O₄/g-C₃N₄), nearly 97% of sertraline was photodegraded at room temperature within 60 min. Kinetic analysis indicated that the degradation followed first-order kinetics, with a rate constant of 0.0536 min^-1. BET analysis revealed that the Co₃O₄/g-C₃N₄ photocatalyst feature a porous nanonet architecture, which provide a high specific surface area due to the presence of g-C₃N₄. Mechanism evaluation suggested that Co₃O₄ primarily generates hydroxyl radicals (^·OH) radicals, while g-C₃N₄ facilities the formation of superoxide radicals (^·O₂^-). The synergistic generation of ^·OH and ^·O₂^- radicals significantly enhances the photocatalytic degradation performance of the Co₃O₄/g-C₃N₄ nanocomposite. Overall, the Co₃O₄/g-C₃N₄ photocatalyst exhibited superior activity, achieving 97% degradation efficiency, compared to pristine Co₃O₄ (68%) and g-C₃N₄ (60%).