Microwave-assisted reduction of graphene oxide for an electrochemical supercapacitor: Structural and capacitance behavior

Abstract

Here, we demonstrate a fast and facile method for rapid production of reduced graphene oxide (rGO) through a microwave-assisted reaction using the green reducing agent sodium cholate at temperatures between 120 and 180 °C for 1 h. Characterization with ultraviolet–visible, Fourier-transform infrared, and Raman spectroscopy confirmed that reduction occurred at each tested temperature. Higher temperatures resulted in greater removal of oxygen-containing functional groups from the graphene oxide (GO). The morphology of GO and rGO samples was observed by field emission scanning electron microscope. The electrochemical properties and cycle performance of rGO samples were evaluated by cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The rGO sample reacted at 140 °C achieved specific capacitance values of up to 293% those of samples reacted at other temperatures. Furthermore, rGO-140 °C demonstrated remarkable capacitance retention, maintaining at 104.1% after 5000 cycles, suggesting that it can be used as a promising electrode material for supercapacitor applications.