Multi-Walled Carbon Nanotube-Gold Nanocomposites toward Oxygen Reduction Reaction

Multi-walled carbon nanotubes (MWCNTs) nanocomposites decorated with Au nanoparticles were prepared by the facile pyrolysis of AuCl3 dissolved in room temperature ionic liquids (RTILs) of 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) in the presence of MWCNTs. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the obtained samples. The results showed that highly crystalline Au particles with an average diameter of 300 nm were fabricated. The electrocatalytic performance of the Au particles modified glassy carbon electrode in the oxygen reduction reaction (ORR) was probed using cyclic voltammetry (CV). The pyrolysis time was noticed to be a key factor, influencing not only the size of Au particles but also the electrocatalytic activity of Au particles towards ORR. It revealed that under the same conditons the Au particles with a diameter close to 300 nm showed the largest current of ORR among the prepared samples.