Spectroscopic characterization and electrocatalytic properties of core-shell Au-Pt nanoparticles

Abstract

Core-shell Au-Pt nanoparticles were synthesized by chemical reduction method. The mean diameter of the nanoparticles was determined to be 27 nm by transmission electron microscope(TEM). The prepared nanoparticles were characterized by ultraviolet-visible(UV-Vis) and infrared transmission spectroscopy. The disappearance of the characteristic peak near 520 nm of Au nanoparticles in UV-Vis spectroscopy confirmed the formation of the core-shell structure. Using infrared transmission spectroscopy, the geminal CO adsorbates that yielded a doublet IR band at around 2110 cm(-1) and 2063 cm(-1) on core-shell Au-Pt nanoparticles were detected for the first time. The core-shell Au-Pt nanoparticles supported on GC (glassy carbon) substrate as electrode exhibited good electrocatalytic properties for the oxidation of adsorbed CO(COad) species. The onset and peak potentials of COad oxidation were negatively shifted 0.45 and 0.11 V, respectively, in referring to the values measured on a bulk Pt electrode.