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 2 ) 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 2 and rGO, RuO 2 /rGO nanocomposite electrodes showed ultra-high capacitive performance. The impact of different RuO 2 loadings in RuO 2 /rGO nanocomposite on their electrochemical performance was investigated by various characterizations. The composite RG-2 with 38 wt.% RuO 2 loadings exhibited a specific capacitance of 1120 F g -1 at 1 A g -1 . In addition, it has an excellent capacity retention rate of 84 % from 1A g -1 to 10 A g -1 , 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 2 /rGO composites prepared by this facile process can be an ideal candidate electrode for high-performance supercapacitors.