Sodium cholate as efficient green reducing agent for graphene oxide via flow reaction for flexible supercapacitor electrodes

Abstract

In this work, sodium cholate (NaC) was used as novel green reducing agent for graphene oxide (GO) reduction at 90 °C and short synthesis time using a continuous segmented flow reaction system. As a comparison, we had used the common reducing agent which is glucose to study its chemical and electrochemical properties. The morphologies of GO and reduced-graphene oxide (rGO) were characterized with X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM), Fourier transformed infrared (FTIR), Raman and Ultraviolet–Visible (UV–Vis) spectroscopy analysis demonstrated that reduction of GO occurred. For electrochemical measurements, the rGO was cast on carbon cloth to investigate the electrochemical performance with cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) measurements. NaC assisted rGO (rGO–NaC) was able to achieve a specific capacitance up to 94 F g−1 at 0.1 A g−1 and remarkable capacitance retention of 103% after 10,000 cycles. A flexible test shows that rGO–NaC bendable at 0°–60°. These results demonstrate that rGO–NaC is promising as flexible supercapacitors electrodes.