Abstract
Graphene oxide (GO) and reduced graphene oxide (rGO) are promising materials for sustainable energy storage due to their excellent conductivity, large surface area, and chemical stability. However, conventional methods of reducing GO often involve toxic chemicals, raising environmental concerns. This study introduces a green solvothermal method to synthesize rGO using L-ascorbic acid and ammonia solution as reducing agents, producing a material referred to as G-rGO for supercapacitor applications. Theoretical calculations suggest that the reduction process significantly enhances the electronic properties and structural integrity of the material. X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and energy-dispersive X-ray (EDX) analysis confirmed the reduction of GO to G-rGO. Electrochemical tests, including cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS), demonstrated that G-rGO performed exceptionally well. It exhibited a high specific capacitance of 401 F/g at 1 A/g and impressive cycle stability of 93% after 10,000 cycles. Theoretical results indicate that these characteristics are attributed to enhanced charge transport and a favorable surface area-to-volume ratio. Additionally, G-rGO achieved an energy density of 200.5 Wh/kg at a power density of 2.5 W/kg, underscoring its potential as an eco-friendly, high-performance electrode material for sustainable energy storage.