Investigation of graphene oxide nanogel and carbon nanorods as electrode for electrochemical supercapacitor

In this study, a gel of graphene oxide (GO) and carbon nanorods obtained from the GO gel were synthesized via a modified Hummer's method and a force-driven reflux process respectively. Scanning electron microscopy (SEM) was used to analyse the morphology of the as-synthesized materials showing gelatinous and nanorods structures for the graphene oxide and carbon materials respectively. X-ray diffraction (XRD) suggests that the synthesized materials have a hexagonal crystal structure and an increased interlayer spacing due to the interlaced molecules of oxygen-containing functional groups. X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX) analysis were employed to confirm the presence of carbon and oxygen functionalities in the synthesized materials. Electrodes fabricated from both materials prove a limit specific capacitance of 436.5 F g⁻¹ and 719.5 F g⁻¹ corresponding to specific capacities of 48.5 mAh g⁻¹ and 80.8 mAh g⁻¹ at a current density of 0.5 A g⁻¹ in a three electrode system with 6 M KOH electrolyte for both the graphene oxide gel and carbon nanorods respectively. The materials show good cycle stability after 3000 cycling at a current density of 5 Ag⁻¹, which implies a great promise as electrodes for supercapacitor applications.