Hybridization of cobalt ferrites nanoparticles with multiwall carbon nanotubes and reduced graphene oxide nanosheets: A path to explore new materials for supercapacitors’ electrode

Nanohybrids play an important role in a continuum of energy storage devices and among them cobalt ferrite (CoFe₂O₄) nanoparticles with multi-walled carbon nanotubes (MWCNTs) and reduced graphene oxide (rGO) nanosheets nanohybrid stands out as versatile nanomaterials due to their high performance for supercapacitor's electrodes. In this study, pure CoFe₂O₄ nanoparticles and their nanohybrids are successfully synthesized by one-pot hydrothermal method with subsequent ultra-sonication. The structural and morphological characterizations are carried out by X-ray diffraction and scanning electron microscopy. The electrochemical performances are investigated by cyclic voltammetry, galvanostatic charging/discharging, and electrochemical impedance spectroscopy in 1 M NaOH aqueous electrolyte. CoFe₂O₄/MWCNTs/rGO nanohybrids exhibited good electrochemical properties with high specific capacitance (592 F/g). More importantly, the specific capacitance of CoFe₂O₄/MWCNTs/rGO nanohybrid asymmetric supercapacitor device retained 89.7 % of initial capacitance after 100 cycles at scan-rate of 100 mV/s. The results suggest that the synthesized CoFe₂O₄/MWCNTs/rGO nanohybrids are promising candidate for supercapacitors electrodes. Moreover, the use of inexpensive carbon materials (rGO, MWCNTs) with transition metal oxides like CoFe₂O₄ provides a novel cost-effective tri-nanohybrid [CoFe₂O₄/MWCNTs/rGO] for commercial energy storage devices.