Assessment of antioxidant activity of pure graphene oxide (GO) and composite V_2O_5/GO using DPPH radical and H_2O_2 scavenging assays

In this research, the Co precipitation method was utilized to synthesize a nanocomposite of vanadium oxide (V_2O_5) and graphene oxide (GO). Pure GO was synthesized by the modified hammers method. Using a 1:2 ratio of GO and V_2O_5 and heating in the oven at 70 °C leading to the formation of V_2O_5/GO nanocomposite. By grafting of GO on V_2O_5 surface, a high range of graphene oxidation in V_2O_5/GO allowed for better reduction with V_2O_5 metal-oxide. The scanning electron microscope (SEM) images and X-ray diffraction (XRD) spectra provide evidence of the distinct phase of graphene oxide formation. The antioxidant activity of V_2O_5/GO nanocomposite was conducted in two vitro assays, focusing on neutralization of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and H_2O_2 radicals. The uniqueness of the nanocomposite was evident from its concentration-dependent antioxidant activities. Interestingly, the V_2O_5/GO samples has showed 60% antioxidant performance in the H_2O_2 assays compared to its constituent. Nanocomposite of V_2O_5/GO was synthesized by grafting of GO on V_2O_5 surface. The oxidation of graphene within the V_2O_5/GO system facilitated improved reduction when combined with V_2O_5 metal oxide. The distinctiveness of the nanocomposite became apparent through its antioxidant activities, which were dependent on its concentration. It is noteworthy that the V_2O_5/GO samples exhibited a 60% higher antioxidant performance in the H_2O_2 tests compared to their individual components.