One-Step Electrosynthesis of Bimetallic Au−Pt Nanoparticles on Indium Tin Oxide Electrodes: Effect of the Deposition Parameters

Bimetallic Au-Pt nanoparticles (Au-PtNPs) were prepd. by 1-step electrochem. redn. of KAuBr4 and K2PtCl4 precursors in acidic media. Characterization of Au-PtNPs was made by SEM, x-ray diffraction, UV-visible spectroscopy, and cyclic voltammetry. The effects of Au and Pt precursors molar ratio and the deposition time were studied. Pt and Au nanoparticles (PtNPs and AuNPs) were also electrosynthesized for comparison. The bimetallic system can be obtained only with 1:1 or 2:1 Au/Pt molar ratio; all the other ratios afford the electrosynthesis of PtNPs and AuNPs in sep. domains. The deposition time seems to affect preliminarily the percentage of surface coverage and not the compn. of the nanoparticles. The electrocatalytic behavior of bimetallic Au-PtNPs catalyst for MeOH oxidn. was studied in alk. conditions; the results show a higher catalytic efficiency for Au70Pt30 compn.