Preparation, characterization and the supercapacitive behaviors of electrochemically re duce d graphene quantum dots/polypyrrole hybrids

Developing advanced materials for energy conversion and storage devices is of significant importance for modern society. In this work, graphene quantum dots (GQDs) were electrostatically self-assembled with polypyrrole (PPy), and then electrochemically reduced GQDs (ERGQDs)/PPy hybrids were obtained via direct electrochemical reduction of the GQDs. The size and distribution of the PPy particles are closely correlated with the concentration of the pyrrole (Py) monomer. The obtained ERGQDs/PPy hybrids combine the advantages of electrical double-layer capacitors (EDLC) from ERGQDs and pseudo-capacitors from PPy, exhibiting high specific capacitance (418 F g -1 at 1 A g -1 ), good rate capability (75.8% capacitance retention at 10 A g -1 ) and high cyclic stability (86.0% capacitance retention after 10 0 0 cycles at 10 A g -1 ). These results indicate that the as-prepared ERGQDs/PPy hybrids might be a promising electrode material for supercapacitors. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

By electrostatic self-assembly and electrochemical reduction, ERGQDs/PPy hybrids were obtained with high specific capacitance, good rate capability, and high cyclic stability, showing potential as electrode materials for supercapacitors.