Publication

Abstract : The size-dependent optical properties, high surface area, tunable surface chemistry, and favourable electrical conductivity of graphene quantum dots (GQDs) make them highly promising for use in optoelectronics and energy storage. GQDs synthesized in powder form can facilitate storage, transport, and integration into devices for sensing, electronics, bioimaging, and supercapacitors. In the current study GQDs with an average size of 6.46 nm are prepared from tender coconut water in the powder form. The graphitic nature and the surface functionalities in the synthesized GQDs were confirmed by the help of FTIR, Raman, XRD and XPS analysis. The powder GQDs are capable of dispersing in water and shows photoluminescence characteristics with a quantum yield of 19.3%. The synthesized GQDs show better electrical conductivities over Graphene Oxide (GO) and better charge transfer performance as evident from the electrochemical studies. Moreover, the synthesized GQDs shows better thermal stability over GO synthesized via Hummer's method. The cyclic voltammetry studies (CV) reveal that GQDs shows a specific capacitance of 10.6 F g−1, which is 27.4 time higher than that of GO.