Synthesis of 3D marigold flower-like rGO/BN/Ni(OH)2 ternary nanocomposites for supercapacitor applications

Abstract

Supercapacitors are efficient and developing energy storage devices. The main focus of this work was on the preparation of reduced graphene oxide supported boron nitride doped-nickel hydroxide [rGO/BN/Ni(OH)₂] nanocomposites through a hydrothermal approach, for studying their electrochemical behaviour and specific capacitance by fabricating supercapacitor devices. Pristine BN, BN/Ni(OH)₂ and rGO/Ni(OH)₂ nanocomposites were also prepared and their use as supercapacitor electrode materials was studied. The structural and morphological properties were characterized using various analytical tools. SEM images showed a spherical shape with a marigold flower-like morphology. The electrochemical behaviour was studied using cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy techniques. The specific capacitances of rGO/BN/Ni(OH)₂ in 0.5 M KOH, 1 M KOH, 3 M KOH, and 6 M KOH were 349, 297 F g⁻¹, 143 F g⁻¹, and 94 F g⁻¹, respectively. It was observed that the capacitance increased with a decrease in the electrolyte concentration and the maximum specific capacitance was noted in 0.5 M KOH. Also, a significant increase in energy density and power density in 0.5 M KOH was observed. These results demonstrate that rGO/BN/Ni(OH)₂ nanocomposites are a promising electrode material for high-performance energy storage devices.