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-C3 N4 ) polymers and cobalt oxide composites effectively. The weight percentage of g-C3 N4 nanoparticles influenced the electrochemical performance of the Co3 O4 -g-C3 N4 composite. In an aqueous electrolyte, the Co3 O4 -g-C3 N4 composite electrode, produced with 150 mg of g-C3 N4 nanoparticles, revealed remarkable electrochemical performance. With an increase in the weight percentage of g-C3 N4 nanoparticles, the capacitive contribution of the Co3 O4 -g-C3 N4 composite electrode increased. The Co3 O4 -g-C3 N4 -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.