Elevating Supercapacitor Performance of Co 3 O 4 -g-C 3 N 4 Nanocomposites Fabricated via the Hydrothermal Method.

The hydrothermal method has been utilized to synthesize graphitic carbon nitride (g-C₃N₄) polymers and cobalt oxide composites effectively. The weight percentage of g-C₃N₄ nanoparticles influenced the electrochemical performance of the Co₃O₄-g-C₃N₄ composite. In an aqueous electrolyte, the Co₃O₄-g-C₃N₄ composite electrode, produced with 150 mg of g-C₃N₄ nanoparticles, revealed remarkable electrochemical performance. With an increase in the weight percentage of g-C₃N₄ nanoparticles, the capacitive contribution of the Co₃O₄-g-C₃N₄ composite electrode increased. The Co₃O₄-g-C₃N₄-150 mg composite electrode shows a specific capacitance of 198 F/g. The optimized electrode, activated carbon, and polyvinyl alcohol gel with potassium hydroxide were used to develop an asymmetric supercapacitor. At a current density of 5 mA/cm², the asymmetric supercapacitor demonstrated exceptional energy storage capacity with remarkable energy density and power density. The device retained great capacity over 6k galvanostatic charge–discharge (GCD) cycles, with no rise in series resistance following cyclic stability. The columbic efficiency of the asymmetric supercapacitor was likewise high. [ABSTRACT FROM AUTHOR]