Effects of oxygen-containing functional groups on the supercapacitor performance of incompletely reduced graphene oxides

•Reduced graphene oxide (RGO) was prepared by the reduction of graphite oxides via microwave irradiation.•The electrochemical performance of the RGO electrodes were measured in different electrolytes.•The effect of oxygen-containing functional groups on the supercapacitor performance was studied.

Incompletely reduced graphene (RG) was prepared by reduction of graphite oxides via microwave irradiation at the power of 800 W and 1200 W, respectively. Fourier transform infrared spectra and X-ray photoelectron spectroscopy analyses showed that the RG contains flourish oxygen functional groups such as carboxyl, phenol, carbonyl, and quinone groups. X-ray diffraction, scanning electron microscopy and transmission electron microscopy were employed to investigate the structure, morphology of the RG samples. The electrochemical performance of the RG electrodes were measured in 5 M NaOH, 1 M H2SO4 and 1 M Na2SO4 electrolytes respectively. The supercapacitor performance of oxygen-containing functional group behavior was investigated. The specific pseudocapacitance per unit atomic percentage for either carboxyl or phenol group in 1 M H2SO4 and either carbonyl and quinone group in 5 M NaOH were obtained by galvano-statically charge/discharge measurements