High-performance graphene oxide electrode synthesized via modified Hummer's method for supercapacitor application

Graphene oxide (GO) was synthesized via the modified Hummers method and characterized using SEM, TEM, EDS, XRD, and UV-Vis spectroscopy to assess its morphology and chemical composition. The structural, morphological, and electrochemical properties of GO were evaluated, with a focus on its performance in supercapacitor applications. Electrochemical studies, including CV, GCD, and EIS, revealed efficient charge storage and rapid electron transfer, with the GO electrode exhibiting a specific capacitance of 147 F/g at 5 mV/s, and energy and power densities of 14.90 Wh/kg and 242.04 W/kg, respectively, at 1.0 mA. The GO/PVA/GO symmetric device exhibits efficient capacitive behavior with rapid, stable charge-discharge performance. CV curves remain quasi-rectangular up to 150 mV/s, and GCD shows rapidly decreasing discharge times with increasing current, indicating fast electrochemical kinetics. EIS confirms low series resistance and charge-transfer resistance, demonstrating good ionic conductivity and strong potential for stable, high-performance supercapacitor applications. Graphene oxide (GO) coated Ni-foam electrode and its electrochemical evaluation in a three-electrode system. • Synthesis and comprehensive characterization of Graphene Oxide nanoparticles confirming their structural and morphological properties. • Detailed electrochemical investigation of GO, revealing high charge storage capacity and rapid electron transfer kinetics. • Demonstration of GO as a promising supercapacitor electrode, exhibiting excellent specific capacitance (147 F/g) and energy/power densities.