Highly efficient photo-adsorptive degradation of tetracycline and metronidazole antibiotics by green synthesized Ag doped CeO2@SnO2 nanocomposites

Abstract

Globally utilization, toxicity, and bioaccumulation of Tetracycline (TC) and Metronidazole (MNZ) have received great attention from researchers during the past decades. In this study, the fabrication of Ag-doped CeO₂@SnO₂ was achieved by a green method using A. indica leaf extract for the efficient removal of selected antibiotic drugs (TC and MNZ) from water. The fabricated nanomaterial’s were characterized by PXRD, FT-IR, FE-SEM, BET, TEM, and XPS techniques. The XRD and BET outcomes showed that synthesized Ag-doped CeO₂@SnO₂ have characteristic crystalline structures with high surface area (102 m²g⁻¹) respectively. FT-IR analysis confirmed the doping of Ag in the CeO₂@SnO₂ nanocomposite. Particularly, the Ag-CeO₂@SnO₂ photocatalysts showed a greater photocatalytic degradation rate for the selected drugs under Sunlight illumination compared to parent photocatalysts. Ag-CeO₂@SnO₂ caused highest degradation (96 %–94 %) of pollutants was found at 10 mg L⁻¹ of TC and 2 mg L⁻¹ of MNZ concentration, 20 mg of photocatalyst dosage, and pH ∼ 7 under sunlight irradiation (5 h) with. The presence of different reactive species (holes, hydroxyl radicals, and superoxide’s radicals was confirmed by the quenchers (t-BuOH, p-BZQ, Na₂EDTA) revealed their significant role for the removal of the targeted pollutants. Formation of safer metabolites after degradation of TC and MNZ was confirmed by GC–MS analysis. Fabricated Nanocomposite (Ag-CeO₂@SnO₂) demonstrated remarkable stability and sustainability by remaining unaltered up to 8th cycles without significant loss in its activity. Present study advocated fabrication of an efficient and alternative photocatalyst for treatment of industrial waste with a bright future.