Deposition time-driven growth of gold nanoparticles for enhanced performance in ethanol electrooxidation

Abstract

Gold nanoparticles (AuNPs) exhibit unique catalytic, electronic, and optical properties, making them highly suitable for various applications, particularly in catalysis. This study explores the synthesis of AuNPs on fluorine-doped tin oxide substrates using a square-wave pulse deposition technique, with deposition time as the primary variable influencing nanoparticles growth. The synthesized AuNPs were systematically characterized using field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction techniques. The electrocatalytic performance of the synthesized AuNPs was evaluated through electrochemical impedance spectroscopy and cyclic voltammetry in an alkaline medium. The results revealed that longer deposition duration led to nanoparticle increased coverage, improved charge transfer kinetics, and enhanced catalytic activity. Notably, AuNPs50 deposited for 50 minutes exhibited the the lowest charge transfer resistance and the highest electrochemical surface area, resulting in the highest current density during ethanol electrooxidation. These findings demonstrate the enhanced catalytic performance of the electrodeposited AuNPs for ethanol oxidation, achieved without the use of surfactants or additives.