A parametric study for the synthesis of graphene–AgAu nanocomposites: performances as electrode material

Abstract

Reduced graphene oxide (rGO)/AgAu bimetallic nanoparticle nanocomposites were prepared with one step simultaneous reduction of graphene oxide, silver nitrate (AgNO3) and chloroauric acid (HAuCl4) using glucose as a reducing agent. The synthesized nanocomposites were characterized by ultraviolet–visible spectroscopy, X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and scanning transmission electron microscope with energy dispersive X-ray line scan analysis. The electrochemical performances of nanocomposites were analyzed by cyclic voltammetry and galvanostatic charge–discharge techniques. The effects of synthesis parameters on the structure and the morphology of graphene–AgAu bimetallic nanoparticle nanocomposites were investigated. The results showed that rGO sheets were successfully reduced and decorated homogenously by AgAu bimetallic nanoparticles with small sizes and narrow particle size distribution, also it was determined, synthesis parameters including reducing agent concentration, alkalinity of the reaction media, the presence of stabilizing agent polyvinylpyrrolidone and reaction temperature had significant effect on the particle size, size distribution and the particle structure of graphene nanosheets decorated with bimetallic nanoparticles. The results showed that rGO/AgAu bimetallic nanoparticle nanocomposite proved to be a promising electrode material for supercapacitors application.