Enhanced visible-light-driven photocatalytic degradation of emerging water contaminants by a modified zinc oxide-based photocatalyst; In-vivo and in-vitro toxicity evaluation of wastewater and PCO-treated water

This study prepared Ga, S co-doped ZnO@reduced graphene oxide nanocomposite by an innovative wet chemical-assisted solvothermal method. The prepared nanocomposites were examined for their ability in the photocatalytic oxidation process (PCO) for detoxification and degradation of Acetaminophen (ACT) solution under visible irradiation. Compared to the pure ZnO, the co-doped catalysts revealed significantly enhanced photocatalytic performance, not only due to improving photogenerated electrons transportation but also by extending optical absorption to the visible light range. The complete degradation and 61% mineralization of 50 mg/L ACT was achieved in the PCO process during 60 min over optimized catalyst (Ga1.0S5.0@ZG). The cytotoxicity of untreated and PCO-treated ACT solutions were evaluated by the use of the HepG2 (Human hepatic cells), which revealed that ACT solution in the developed PCO system could be significantly detoxified. In-vivo study suggested treated solutions in the developed PCO reaction could considerably prevent the hepatotoxicity and nephrotoxicity effect of ACT.