Effect of the particle size of graphene oxide powders on the electrochemical performance of graphene-based supercapacitors

Graphene has been extensively investigated as an electrode material for high-performance supercapacitors due to its high electrical conductivity and large surface area. Because conventional graphene-based supercapacitors use reduced graphene oxide (rGO) in a powder form, the particle size can be one of the important factors affecting the supercapacitor performance. In this study, the effect of the particle size of graphene oxide (GO) powders was studied for the electrochemical performance of graphene-based supercapacitors. The GO powders with three different particle size distributions were used for the electrochemical tests after reducing the GO powders using simple microwave irradiation. The chemical characteristics and specific surface areas of the rGO powders synthesized by microwave irradiation (MWrGO) were nearly the same for all cases. However, the supercapacitor using the MWrGO powders with a medium size showed a higher specific capacitance (109.1 F g(-1)) with a lower internal resistance and efficient charge transfer. This work provides an effective method to enhance the electrochemical performance of the MWrGO powders.