Microwave-assisted synthesis of graphene oxide–cobalt ferrite magnetic nanocomposite for water remediation

Abstract

Graphene oxide–cobalt ferrite magnetic nanocomposite (M-GOC) was efficiently synthesised by microwave-assisted method for water remediation. The graphene oxide (GO) was synthesized by improved Hummers’ method, while cobalt ferrite (CoFe₂O₄) was synthesized by microwave-assisted combustion method. X-ray diffractograms indicated high phase-pure M-GOC with an average crystallite size of 18.5 nm. An enhancement in the absorbance was observed in the range of 220–280 nm due to the presence of additional π–π* transition of aromatic C–C bonds of GO. Appearance of a peak around 584 cm⁻¹ corresponds to the stretching vibration of Co–O bond. Corrugated GO sheets were observed in SEM and HRTEM images with agglomerated spherical CoFe₂O₄ nanoparticles intercalated between the GO sheets. A particle size distribution curve was plotted that indicated an average particle size of ~11 nm of the CoFe₂O₄ nanoparticles. Raman spectra of GO confirmed the synthesis of pure GO sheets. Vibrating sample magnetometer was employed to investigate the magnetic behaviour of M-GOC, which showed a M_r/M_s ratio of 0.278. The adsorption study was performed, in which M-GOC nanocomposite exhibited an excellent adsorption capacity of 2229.9 mg g⁻¹ for heavy metal i.e., cadmium ions (Cd⁺²).