g-C3N4/CuO and g-C3N4/Co3O4 nanohybrid structures as efficient electrode materials in symmetric supercapacitors

Metal oxide dispersed graphitic carbon nitride hybrid nanocomposites (g-C3N4/CuO and g-C3N4/Co3O4) were prepared via a direct precipitation method. The materials were used as an electrode material in symmetric supercapacitors. The g-C3N4/Co3O4 electrode based device exhibited a specific capacitance of 201 F g(-1) which is substantially higher than those using g-C3N4/CuO (95 F g(-1)) and bare g-C3N4 electrodes (72 F g(-1)). At a constant power density of 1 kW kg(-1), the energy density given by g-C3N4/Co3O4 and g-C3N4/CuO devices is 27.9 W h kg(-1) and 13.2 W h kg(-1) respectively. The enhancement of the electrochemical performance in the hybrid material is attributed to the pseudo capacitive nature of the metal oxide nanoparticles incorporated in the g-C3N4 matrix.