One-pot synthesis of reduced graphene oxide/chitosan/zinc oxide ternary nanocomposites for supercapacitor electrodes with enhanced electrochemical properties

The ternary nanocomposite of reduced graphene oxide/chitosan/ZnO (RGO/Cs/ZnO) was synthesized by a facile one-step hydrothermal route. The structure-capacitive performance relationships and the effect of the prolonged time of hydrothermal process for supercapacitor applications are studied. In the prolonged hydrothermal process of 20 h, the ternary nanocomposite exhibits more homogeneously ZnO nanoparticles and chitosan distributed on finer layers of graphene nanosheet. Interestingly, it shows both increased conductivity and electroactive sites. As a result, it enhances electrochemical properties for a supercapacitor device, reaching the highest specific capacitance of 137.7 F/g at 0.5 A/g and capacitance retention attains excellent cyclic stability of 97.4% after 5000 cycles at a current density of 2 A/g.