Silver-Decorated Cobalt Ferrite Nanoparticles Anchored onto the Graphene Sheets as Electrode Materials for Electrochemical and Photocatalytic Applications

M A Majeed Khan; Wasi Khan; Maqusood Ahamed; Jahangeer Ahmed; M A Al-Gawati; Abdulaziz N Alhazaa

doi:10.1021/acsomega.0c04191

Silver-Decorated Cobalt Ferrite Nanoparticles Anchored onto the Graphene Sheets as Electrode Materials for Electrochemical and Photocatalytic Applications

ACS Omega. 2020 Nov 25;5(48):31076-31084. doi: 10.1021/acsomega.0c04191. eCollection 2020 Dec 8.

Authors

M A Majeed Khan¹, Wasi Khan², Maqusood Ahamed¹, Jahangeer Ahmed³, M A Al-Gawati⁴, Abdulaziz N Alhazaa^{1

4}

Affiliations

¹ King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia.
² Department of Physics, Aligarh Muslim University, Aligarh 202002, India.
³ Department of Chemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
⁴ Physics and Astronomy Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.

Abstract

The present work describes the synthesis of Ag-CoFe₂O₄/rGO nanocomposite as a photocatalyst through the hydrothermal process by the attachment of silver and cobalt ferrite (CoFe₂O₄) nanoparticles on the surface of reduced graphene oxide. The effect of Ag and reduced graphene oxide (rGO) on the structure, optical, magnetic, photocatalytic, and electrochemical performance of the CoFe₂O₄ is systematically explored through various analytical techniques. The analyses of the observed outcomes reveal that the graphene sheets are exfoliated and decorated with well-dispersed Ag and CoFe₂O₄ nanoparticles. UV-vis spectra indicate a gradual shift in the absorption edge toward the higher wavelength with the addition of Ag ions, which signifies variation in the energy gap of the samples. Photoluminescence results divulge that graphene can decline the electron-hole recombination rate and improve the photocatalytic activity of the Ag-CoFe₂O₄/rGO nanocomposite. In this context, the Ag-CoFe₂O₄/rGO sample presents good catalytic activity as compared to the CoFe₂O₄ and Ag-CoFe₂O₄ photocatalysts for the degradation of methylene blue (MB) dye and suggests that the rGO plays a vital role in the Ag-CoFe₂O₄/rGO nanocomposite. The deterioration rate of the samples is found to be 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. The room-temperature ferromagnetic behavior of the samples is confirmed by the M-H hysteresis loop measurements. Overall, the Ag-CoFe₂O₄/rGO nanocomposite promises to be a strong magnetic photocatalyst for contaminated wastewater treatment. The electrochemical performance of all of the samples was examined by the cyclic voltammetry (CV) that exhibits a superior rate performance and cycle stability of the Ag-CoFe₂O₄/rGO nanocomposite as compared to the other samples.