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.