Interfacial engineering of reduced graphene oxide for high-performance supercapacitor materials

Abstract

To solve the problems related to the re-stacking of reduced graphene oxides (rGO) and further improve their surface chemical behaviors to satisfy supercapacitor demands. The rGO decorated with graphene quantum dots has been successfully prepared via a facile low-power ultrasonic method. It is demonstrated the graphene quantum dots/reduced graphene oxide electrode has a high specific capacitance of 312 F g −1 , which is nearly three times higher than that of the reduced graphene oxide (132 F g −1 ). The enhanced super-capacitive performances of graphene quantum dots/reduced graphene oxide have been attributed to the introduction of graphene quantum dots, which effectively prevent the aggregation and restacking of reduced graphene oxide sheets, promoting its surface exposed to the electrolyte for sufficient mass transfer. Meanwhile, these features provide more pathways for the transportation of electrons between the interlayer of reduced graphene oxide sheets. Afterward, a detailed energy storage mechanism was analyzed. • Graphene quantum dots reduced the agglomeration of reduced graphene oxide. • More channels for the electrolyte transport into the interlayer of RGO sheets. • The electrode and device exhibit excellent electrochemical performance.