Enhanced photocatalytic activity of V2O5 /g-C3N4 /ZnO nanocomposite for efficient degradation of Amoxicillin, Chlorpyrifos and Methylene blue

Abstract In the present research investigation, a novel nanocomposite viz. V₂O₅/g-C₃N₄/ZnO was synthesized using wet impregnation technique. Its photocatalytic degradation performance was assessed against various organic pollutants including the antibiotic Amoxicillin (AMX), the pesticide Chlorpyrifos (CPF), and the dye Methylene Blue (MB), under the effect of visible light in an aqueous medium. The materials synthesised and their photodegradation effectiveness were systematically characterized by a variety of techniques including XRD, HR-SEM, TEM, EDS, XPS, UV-DRS, PL, BET, and EIS. XRD spectra confirmed the existence in the hexagonal phase of g-C₃N₄, the hexagonal wurtzite structure in ZnO, and the orthorhombic phase in V₂O₅. The corresponding plane in the V₂O₅/g-C₃N₄/ZnO nanocomposite was also identified. The HR-SEM images depicted a composite of nanosheets and nanorods within the nanocomposite. The synthesized photocatalyst revealed an effective visible light absorption with a bandgap of 2.5 eV and displayed remarkable photocatalytic degradation efficiencies of 93.23% for MB, 62.02% for CPF, and 55.36% for AMX when exposed to visible light for 90 minutes. This proved its higher efficiency than that of individual components viz. g-C₃N₄, ZnO, and V₂O₅. The hydrogen ions (h⁺) and superoxide ions (O₂•−) were found to be the key reactive species, which are involving in the photodegradation process by radical scavenging tests. Furthermore, the present nano photocatalyst proved its remarkable photocatalytic stability even after three cycles, showing its favorable chemical properties. The findings imply that this reported photocatalyst is highly suitable for efficiently photodegrading the organic pollutants in aqueous environments.