Reduced Graphene Oxide Decorated with Dispersed Gold Nanoparticles: Preparation, Characterization and Electrochemical Evaluation for Oxygen Reduction Reaction

Abstract

The commonly used electrode Pt supported on a carbon (Pt/C) catalyst has demonstrated underperforming electrochemical durability in proton exchange membrane fuel cell (PEMFC) harsh operation conditions, especially in terms of Pt electrochemical instability and carbon corrosion. Gold nanoparticles (AuNPs) are considered one of the best alternative catalysts of PtNPs due to their remarkable selectivity for oxygen reduction reaction (ORR) and electrochemical stability in strong acid conditions, attributes which are ideal for practical PEMFC applications. In this work, we propose a new, facile and low-cost approach to prepare AuNPs supported on reduced graphene oxide nanocompounds (AuNPs/rGO). The morphological and structural properties of the as-prepared AuNPs/rGO were studied using various microscopic and spectroscopic techniques, namely, Raman Spectroscopy, Scanning Electron Microscopy (SEM), Scanning Transmission Electron Microscopy (STEM), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), specific surface area (Brunauer–Emmett–Teller, BET). A mesoporous structure with narrow pore size distribution centered at 2 nm approximately, where the pores are regular and interconnected was successfully fabricated. The prepared catalyst was exposed to an accelerated stress test (potential cycles between −0.8 and +0.2 in KOH 1 M solution). The voltammetric stability test indicated a slight degradation after 1500 cycles. The electrochemical stability was assigned to the combined effect of AuNPs formed during chemical synthesis and to graphene oxide support.