Electrochemical performance of graphene-oxide (GO) and MOF5-GO nanocomposite

In current research work, the electrochemical study of the graphene-oxide (GO) and its nanocomposite (MOF5-GO) was done in a three-electrode system (3E). GO was synthesized by the modified Hummer method, and the nanocomposite was prepared via a facile, cost-effective, and environmentally friendly solvothermal technique. X-ray diffraction (XRD) and SEM were used to analyze the sample’s structure and morphological details. Further, the as-prepared GO and MOF5-GO were studied as electrodes in aqueous electrolyte (6 M KOH). The pore radius and specific surface area (S_BET) of the GO and MOF5-GO were found to be 1.9 nm and 0.603 m²/g, and 2.1 nm (mesopores) and 1.61 m²/g, respectively, as confirmed by Brunauer–Emmett–Teller (BET) examination. The results of the electrochemical testing utilizing cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) measurements indicated a higher specific capacitance of the nanocomposite compared to the GO at different current densities. The electrochemical impedance spectroscopy (EIS) spectra indicate low internal resistance (R_S) and charge transfer resistance (R_CT) for GO and MOF5-GO nanocomposite, suggesting high conductivity. In the 3E system, the GO and MOF5-GO electrodes demonstrated specific capacitance of 73.95 F/g and 108.45 F/g at 3 A/g, respectively. Additionally, after 2000 charge–discharge cycles at 5 A/g, the GO and MOF5-GO electrodes retained approximately 80% and 86.5% of their initial capacitance, respectively. These findings collectively suggest that MOF5-GO is a viable material for electrodes with fantastic characteristics for supercapacitors.