Synergistic integration of rGO into cobalt oxide matrix for efficient electrochemical performance mediated by structural stability

Abstract

The growing global challenges have prompted researchers to create efficient energy production and storage tools. In our quest to find optimal electrode materials for supercapacitors to meet energy demands, we embarked on an intriguing journey with electrochemically efficient Co3O4 composites integrated with reduced graphene oxide (rGO) in various wt% (5 %, 10 %, and 15 %). The citrate–gel auto-ignition approach was employed to synthesize Co3O4, followed by the solvothermal technique for Co3O4/rGO composite formation. Structural characterization through X-ray diffraction unveiled the spinel cubic crystallinity of Co3O4 and exposed a reduction in crystallite size with the addition of rGO. Morphological features examined by field emission scanning electron microscope revealed small grain size and porosity variation directly influenced by varying rGO concentrations, while energy dispersive X-ray confirmed the existence of different constitutional elements. The comprehensive electrochemical analysis confirmed the pseudocapacitive nature of as-synthesized electrodes via cyclic voltammetry in a 2 M KOH solution. Meanwhile, galvanostatic charge-discharge displayed CO-III has a maximum specific capacitance (1478 Fg−1), energy (74 Whkg−1), and power densities (0.90 kWkg−1) with 83 % retention at 3 Ag−1 suggesting its potential suitability for supercapacitor applications.