Concentration-dependent kinetic study of graphene oxide (GO) reduction using biophenol and electrochemical analysis†

Graphene, a two-dimensional material, has garnered significant interest among researchers globally due to its exceptional characteristics, including a substantial surface area, remarkable chemical stability, elevated electron mobility, and electrical conductivity. The present study explored the synthesis of reduced graphene oxide (rGO), a derivative of graphene materials, by the utilization of gallic acid as a green reducing agent. The successful reduction of graphene oxide (GO) was assessed by X-ray diffraction, UV-vis spectroscopy, Raman, Transmission Electron Microscopy (TEM), and X-ray photoelectron spectroscopy. Cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) investigations were employed to analyze the electrochemical and capacitive performance of reduced graphene oxide (rGO). The specific capacitance of rGO was determined to be 301.7 F g⁻¹ at a current density of 1 A g⁻¹. The electrode exhibits an energy density of 121.1 W h kg⁻¹ at a power density of 853.2 W kg⁻¹, and has an exceptional cycle stability of 91% after undergoing 2000 cycles. This green reduction technique is environmentally friendly and shows promising reduction of graphene oxide (GO) into reduced graphene oxide (rGO). Additionally, the prepared rGO exhibited improved electrochemical and capacitive properties showcasing its potential use in supercapacitor applications.