Electrochemical deposition of gold–platinum alloy nanoparticles on an indium tin oxide electrode and their electrocatalytic applications

Gold–platinum (Au–Pt) hybrid nanoparticles (Au–PtNPs) were successfully deposited on an indium tin oxide (ITO) surface using a direct electrochemical method. The resulting nanoparticles were characterized by scanning electron microscopy (SEM), UV–vis spectroscopy, X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and electrochemical methods. It was found that the size of the Au–PtNPs depends on the number of electrodeposition cycles. Au–PtNPs obtained by 20 electrodeposition cycles had a cauliflower-shaped structure with an average diameter of about 60 nm. These Au–PtNPs exhibited alloy properties. Electrochemical measurements showed that the charge transfer resistivity was significantly decreased for the Au–PtNPs/ITO electrode. Additionally, the Au–PtNPs displayed an electrocatalytic activity for nitrite oxidation and oxygen reduction. The Au–PtNPs/ITO electrodes reported herein could possibly be used as electrocatalysts and sensors.