A comparative study on the charge storage performance of graphene oxide and reduced graphene oxide in different electrolytes with basic and neutral behaviour

A comparative study on electrochemical supercapacitance performance of graphene oxide (GO) and reduced graphene oxide (rGO) was conducted in neutral and alkaline electrolytes, including Na 2 S 2 O 3 and KOH. rGO has been prepared through hydrothermal reduction of GO. Before hydrothermal reduction, GO was prepared from bulk graphite via low temperature modified Hummer’s method. The oxygen functional groups were found favourable for base-activated pseudocapacitive reactions that make GO superior to deliver improved supercapacitor performance in KOH electrolytes. On the other hand, a significant increase in effective surface area during hydrothermal reduction make rGO perform better as an electrochemical double-layer capacitor in neutral electrolyte, like sodium thiosulphate. rGO achieved an optimum specific capacitance value of 287 F g –1 in Na 2 S 2 O 3 , while GO reported 127 F g –1 in 1 M KOH at 1 A g –1 current density.