Electrodeposited gold nanoparticles on glassy carbon: Correlation between nanoparticles characteristics and oxygen reduction kinetics in neutral media

Guillaume Gotti (1, 2) , Katia Fajerwerg (2) , David Evrard (1) , Pierre Gros (1)

1 LGC - Laboratoire de Génie Chimique
2 LCC - Laboratoire de chimie de coordination

Gold nanoparticles (AuNPs) were deposited onto glassy carbon (GC) by constant potential electrolysis (CPE) using various sets of potential and duration from -0.3 to 0.7 V and 10 to 1800 s, respectively. The physico-chemical characteristics of the as-obtained deposits were investigated by cyclic voltammetry (CV) in H2SO4, field emission gun scanning electron microscopy (FEG-SEM), and Pb underpotential deposition (UPD). Their performances towards the oxygen reduction reaction (ORR) in a NaCl-NaHCO3 (0.15 M / 0.028 M, pH 7.4) neutral solution were examined and correlated to AuNPs size and density. The best results were obtained using the deposits which exhibited a high density (555 +/- 49 µm-2) of relatively small AuNPs (25 +/- 12 nm). The Koutecky-Levich treatment was systematically applied to all the deposits in order to determine the number of electrons n exchanged for the ORR in the potential range from 0.1 to -1 V. The values of the cathodic transfer coefficients Beta n were also extracted and compared to the values reported for unmodified GC and bulk Au. A map of the Beta n values as a function of AuNPs electrodeposition potential and duration was also provided.

Mots clés: Oxygen reduction reaction; Neutral media; Koutecky-Levich analysis; Electrochemical kinetics; Gold nanoparticles electrodeposition

Domaines: Génie chimique

Guillaume Gotti, Katia Fajerwerg, David Evrard, Pierre Gros. Electrodeposited gold nanoparticles on glassy carbon: Correlation between nanoparticles characteristics and oxygen reduction kinetics in neutral media. Electrochimica Acta, 2014, vol. 128, pp. 412-419. ⟨10.1016/j.electacta.2013.10.172⟩. ⟨hal-00977362⟩