Electrochemical and Photocatalytic Applications of Silver-doped Cobalt Ferrite Anchored on Graphene Sheets

Abstract

The current study describes the synthesis of anAg-CoFe₂O₄/rGO nanocomposite as a photocatalyst via a hydrothermal process that involves the attachment of silver and cobalt ferrite (CoFe₂O₄) nanoparticles to the surface of reduced graphene oxide. Various analytical techniques are used to investigate the effect of Ag and reduced graphene oxide (rGO) on the structure, optical, magnetic, photocatalytic, and electrochemical performance of CoFe₂O_4. The results show that the graphene sheets are exfoliated and decorated with well-dispersed Ag and CoFe₂O₄ nanoparticles. UV-visible spectra show a gradual shift in the absorption edge towards higher wavelengths with the addition of Ag ions, indicating variation in the samples' energy gap. The photoluminescence results show that graphene can reduce electron-hole recombination and improve the photocatalytic activity of the Ag-CoFe₂O₄/rGO nanocomposite. In this sense, theAg-CoFe₂O₄/rGO sample exhibits superior catalytic activity to the CoFe₂O₄ and Ag-CoFe₂O₄ photocatalysts for the degradation of methylene blue (MB) dye, indicating that rGO plays an important role in the Ag-CoFe₂O₄/rGO nanocomposite. The deterioration rate of the samples is found in the order of CoFe₂O₄(78.03%) <Ag-CoFe₂O₄(83.04%) < Ag-CoFe₂O₄/rGO(93.25%) in 100 min for MB dye respectively, under visible light irradiation. M-H hysteresis loop measurements confirm the samples' room temperature ferromagnetic behaviour. Overall, the Ag-CoFe₂O₄/rGO nanocomposite appears to be a strong magnetic photocatalyst for the treatment of contaminated wastewater. The electrochemical performance of all samples was examined using cyclic voltammetry (CV), which reveals that the Ag-CoFe₂O₄/rGO nanocomposite outperforms the other samples in terms of rate performance and cycle stability.