Construction of NiCo₂O₄/O-g-C₃N₄ Nanocomposites: A Battery-Type Electrode Material for High-Performance Supercapacitor Application

In this work, NiCo2O4/O-g-C3N4 nanocomposites (abbreviated as NCO/O-g-CN) have been synthesized using a multistep synthesis process. The transformations of g-C3N4 to oxygenated g-C3N4 during the synthesis of NiCo2O4/O-g-C3N4 nanocomposites trigger electrochemical performances toward supercapacitor application. From the electrochemical study, the NCO/O-g-CN nanocomposite electrode was found to possess battery-type features and shows an outstanding specific capacity of 438.1 C/g at a current density of 1 A/g in a three-electrode system, which is higher than that of pristine NCO and g-CN. It has also gained excellent long-term cyclic stability performance, and its capacity retention was found to be 93.15% after 10 000 cycles at a current density of 4 A/g. The excellent performance of the NCO/O-g-CN nanocomposite indicates synergistic effects of the individual materials toward the improved specific capacity performance. Furthermore, to evaluate the predominant mechanism followed by the NCO/O-g-CN nanocomposite, the Trasatti plot was used, and it was found to be 94.79% for the diffusion-controlled charge component and 5.20% for capacitive contribution. This finding shows that the NCO/O-g-CN nanocomposite can be used as a potential electrode material and might have promising applications in high-performance energy storage devices.