Graphene quantum dots decorated on spinel nickel cobaltite nanocomposites for boosting supercapacitor electrode material performance

Composites of transition metal oxides, with carbon, have been considered to be appropriate materials for enhancing their electrochemical properties in supercapacitor applications. In this study, we prepare Nickel-Cobaltite/Graphene Quantum Dots (NiCo2O4/GQDs) composite structures that exhibit improved electrical conductivity and function as electrode materials with higher energy density in comparison to GQDs and NiCo2O4. The electrochemical performance of NiCo2O4/GQDs is confirmed through galvanostatic charge-discharge method for three electrode systems with an electrolyte of 0.1 M potassium hydroxide. The ob-served specific capacitance for the fabricated composite has been found to be 481.4 Fg(-1) at 0.35Ag(-1). It is higher than that of Graphene Quantum Dots (C-sp similar to 45.6 Fg(-1)). This is due to the enhancement in the electrical conductivity and diffusion of ions which become faster between electrodes and electrolyte. These findings demonstrate the unique characteristics of the fabricated composites as superior electrode materials for applications in supercapacitors. (C) 2021 Elsevier B.V. All rights reserved.