No abstract

Biomass-derived CDs were prepared via a green one-step synthetic method. The orange juice biomass was used as a CD precursor. The resulting CDs were mixed with rGO under the hydrothermal condition to prepare rGO/CD composites with the variation of rGO:CD mass ratio. The composites were characterized through both physical and electrochemical methods. Moreover, the capacitive property of rGO/CD composites in 2 M KOH aqueous electrolyte was studied by cyclic voltammetry, galvanostatic charge-discharge measurements, and electro-chemical impedance spectroscopy. The rGO/CD composite with a 4:1 mass ratio exhibits the high specific capacitance with 184.8 F g-1 at a current density of 0.5 A g-1. The rGO/CD 4:1 composite retains 97.3% of its initial capacitance after 1000 cycles at the current density of 10 A g-1 in 2 M KOH electrolyte solution.