Ultra-Fine Ruthenium Oxide Quantum Dots/Reduced Graphene Oxide Composite as Electrodes for High-Performance Supercapacitors.

This study synthesized ultra-fine nanometer-scaled ruthenium oxide (RuO) quantum dots (QDs) on reduced graphene oxide (rGO) surface by a facile and rapid microwave-assisted hydrothermal approach. Benefiting from the synergistic effect of RuO and rGO, RuO/rGO nanocomposite electrodes showed ultra-high capacitive performance. The impact of different RuO loadings in RuO/rGO nanocomposite on their electrochemical performance was investigated by various characterizations. The composite RG-2 with 38 wt.% RuO loadings exhibited a specific capacitance of 1120 F g at 1 A g. In addition, it has an excellent capacity retention rate of 84 % from 1A g to 10 A g, and excellent cycling stability of 89% retention after 10,000 cycles, indicating fast ion-involved redox reactions on the nanocomposite surfaces. These results illustrate that RuO/rGO composites prepared by this facile process can be an ideal candidate electrode for high-performance supercapacitors.