Influence of sintering temperature on graphitic carbon nitride nanosheets grafted binary metal oxide for high performance asymmetric supercapacitors

This study investigates the impact of different temperatures on the preparation of graphitic carbon nitride nanosheets grafted nickel cobalt oxide (GCN-NS-g-NiCo2O4) by one-step pyrolysis method. X-ray diffraction and X-ray dispersive analysis reveals the crystal structure and the elemental formation of GCN-NS-g-NiCo2O4 nanocomposites. The morphology and porosity was examined by field-emission electron microscope. The resulting nanocomposites demonstrate a high specific capacitance, making them a promising electrochemical behaviour which is suitable for supercapacitor applications. The GCN-NS-g-NiCo2O4@350 electrodes facilitate rapid Faradaic reaction in aqueous 6.0 M KOH electrolyte, and deliver the highest specific capacitance of 268.71 F/g at 0.5 A g(-1). Moreover, the GCN-NS-g-NiCo2O4@350//AC asymmetric device was fabricated, which exhibits high specific capacitance of 44.5 F/g at 0.5 A/g with higher cycling performance (similar to 94 % retention after 2000 cycles).