Boosting electrochemical performance of NiCo2O4 via graphene quantum dot integration

The development of nanocomposite metal oxide electrodes is also under consideration as a bright future of the search for sustainable energy production since it is promising to perform better, be more durable and environmentally friendly. In this case, the nanosheets made of nickel- cobalt oxide (NiCo₂O₄) were prepared, and their electrochemical functions were modified by attaching them with graphene quantum dots (GQDs) to facilitate their application in the supercapacitors and with the maximum level of efficiency. NiCo₂O₄/GQD nanocomposites with small calcifications were obtained using a single hydrothermal reaction that optimized the various parameters, such as concentration of precursors, reaction time, and temperature at which the calcification was done to optimize the morphology and crystallinity. Their structural, morphological and optical properties were studied using the assistance of the X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM, TEM), Raman spectroscopy and the UV- Vis diffuse reflectance spectroscopy. Electrochemical characterization (cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy) revealed that, the NiCo₂O₄/GQD electrode has a large specific capacitance, about 884 F/g, at 1 A/g, good rate performance, which is capable of retaining around 81.5 percent of the capacity at 10 A/g and stability of the cycles up to 5000 cycles with a retention rate of a rate of more than 90 percent The stability of the environment in diverse pH electrolyte and ambient conditions were also tested with the help of the tests. The synergistic effect can be used to explain this performance enhancement, the GQDs can be functionalized to enhance electrical conductivity, in addition to adding active sites to the surface besides its morphology, the nanosheet, can offer diffusion pathways that short ions in an electrolyte, and contacts. As it has been discussed in this paper, NiCo₂O₄ / GQD composites may be highly promising because they are a legitimate device of green and efficient energy storage and might be deployed as handheld electronic devices or grid stabilization.