Analysis of CNT and rGO Mediation for an Efficient Super-Capacitive Response in Cr-Doped Co₃O₄ Based Composites

The synthesis of novel and high capacitance electrode materials has attracted much attention over the last few decades to meet the needs of electrode materials in supercapacitors. Cobalt oxide, one of several vanadium oxides, has recently gained popularity due to its unique layered structure, phase transition, and applications in supercapacitors. Here, we present structural, morphological, and electrochemical analysis of Cr-doped Co3O4 nanostructures and their carbon nanotubes/reduced graphene oxide (CNT/rGO) based composites. Hydrothermal and solvothermal routes are followed to prepare the samples. The active material is developed via a polymer-based binder and is used as the electrode in a three-electrode electrochemical system. X-ray diffraction confirms the spinel-type cubic crystal structure, while the stoichiometric elemental contents are verified via an energy dispersive X-ray spectroscopy. Well-shaped layered growth of the nanocomposites is revealed by field emission scanning electron microscopy. The electrochemical analysis is performed using a 2 M KOH electrolyte solution and a three-electrode electrochemical setup. The pure and Cr-doped nanocomposite samples reveal a pseudo capacitive behavior in all samples. The systematic capacitive and resistive response of the samples has also been presented in this report. The aforementioned attributes make the synthesized specimen a potential candidate for an electrode material.