Facile synthesis of 2D Ni(OH)2 anchored g-C3N4 as electrode material for high-performance supercapacitor

Abstract

Hexagonal nickel hydroxide (Ni(OH)2) nanosheets were directly grown over layered graphitic carbon nitride (g-C3N4) by facile hydrothermal route. To further exploit its potential charge storage mechanism was investigated by varying the weight percentage of g-C3N4 (10, 20 and 30) in the composites of Ni(OH)2/g-C3N4. The as-prepared composites of Ni(OH)2/g-C3N4 exhibits a specific capacitance of 668 F g−1 at the current density of 1 A g−1 in 3 M LiOH electrolyte in comparison with its individual components Ni(OH)2 (261 F g−1 at 1 A g−1) and g-C3N4 (115.6 F g−1 at 1 A g−1). As well the composite has excellent cycle stability, with the capacitance retention of 96.1% after 3000 cycles and shows a columbic efficiency of 93.9%. The improved energy storage properties of the as-fabricated electrodes are due to the redox activity of nickel species (pseudocapacitance) and effective ion diffusion and electron transfer between the electrolyte and the electrode facilitated by the conductive porous structure of graphitic carbon nitride. These results specify the prepared electrode material is a viable nominee for high-performance supercapacitors.