Synthesis of supported Pt nanoparticles by sonication for ORR: Effect of the graphene oxide-carbon composite

Pt supported on graphene oxide (GO), reduced graphene oxide (RGO), carbon Vulcan (C) and GO-C composite were prepared by using sonication as a simple synthesis method in the absence of any special capping agent or thermal treatment. X-ray diffraction (XRD), Raman spectroscopy, Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) techniques were used to characterize the materials synthesized. The electrocatalysts synthesized were evaluated for oxygen reduction reaction (ORR) in acid medium by using cyclic and linear voltammetry tests. The characterization results indicated that the highest dispersion of small Pt particles was observed on the samples supported on GO materials compared to carbon Vulcan due to the oxygen functional surface groups, which promoted a homogeneous distribution of Pt nanoparticles. The electrochemical characterization indicated that Pt/GO-C composite exhibited a 50% more specific and mass activity at 0.85 V for ORR than the conventional Pt/C catalysts, which is associated to Pt-support interaction that modifies the electronic properties of Pt for electrochemical application in fuel cell. GO-C (1:1) can be a promising support for improving the electrochemical activity for ORR.