g-C(3)N(4)/CuO and g-C(3)N(4)/Co(3)O(4) nanohybrid structures as efficient electrode materials in symmetric supercapacitors

Metal oxide dispersed graphitic carbon nitride hybrid nanocomposites (g-C(3)N(4)/CuO and g-C(3)N(4)/Co(3)O(4)) were prepared via a direct precipitation method. The materials were used as an electrode material in symmetric supercapacitors. The g-C(3)N(4)/Co(3)O(4) electrode based device exhibited a specific capacitance of 201 F g(−1) which is substantially higher than those using g-C(3)N(4)/CuO (95 F g(−1)) and bare g-C(3)N(4) electrodes (72 F g(−1)). At a constant power density of 1 kW kg(−1), the energy density given by g-C(3)N(4)/Co(3)O(4) and g-C(3)N(4)/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-C(3)N(4) matrix.