Tuning Electrocatalytic Activity of Gold Silver Nanoparticles on Reduced Graphene Oxide for Oxygen Reduction Reaction
Kristina Radinović, Dušan Mladenović, Jadranka Milikić, Mabkhoot Alsaiari, Farid A. Harraz, Diogo M.F. Santos, Biljana Šljukić
Abstract
Gold-silver (AuAg) nanoparticles were deposited on reduced graphene oxide (rGO), with Au wt% varying from 34.6 to 46.2 and Ag wt% ranging from 31.7 to 35.3. Three AuAg/rGO samples were characterized by inductively coupled plasma optical emission spectroscopy, transmission and scanning electron microscopy with energy-dispersive X-ray spectroscopy, and X-ray diffraction analysis. Subsequently, AuAg/rGO materials were studied using the rotating disk electrode as electrocatalysts for oxygen reduction reaction (ORR) for potential application in alkaline fuel cells. AuAg/rGO-3 (with ca. 34.6 wt% Au and 35.3 wt% Ag) showed the most promising performance, with high ORR activity and good stability, as evidenced by the highest current density (−4.45 mA cm −2 at 0.5 V), the lowest Tafel slope (103 mV dec −1 ), and the highest number of electrons exchanged (4.1).