A Bifunctional Nano-Electrocatalyst Based on a Flower-like Gold/Palladium Bimetallic Alloy Nanostructure and Its Graphene Hybrid

Abstract

This work demonstrates the one-pot, seed-free synthesis of unique flower-like Au/Pd alloy nanostructures and their self-assembly on a graphene support in an aqueous medium. The as-prepared nanostructures were characterized thoroughly by TEM, UV/Vis spectrophotometry, XRD, and X-ray photoelectron spectroscopy (XPS). The bifunctional electrocatalytic activity towards the oxidation of methanol and reduction of oxygen was investigated thoroughly. The results reveal that the Au/Pd alloy nanostructures show a composition-dependent electrochemical activity. The Au/Pd alloy nanostructure with a flower-like morphology shows superior electrocatalytic activity compared to its monometallic Pd counterpart and a commercially available Pd/C. Furthermore, the graphene support tunes the electrocatalytic performance of the Au/Pd alloy nanoflowers and substantiates their promising energy-conversion applications for use in fuel cells.