In situ preparation of multi-wall carbon nanotubes/Au composites for oxygen electroreduction

Abstract

Multi-wall carbon nanotubes (CNTs)/Au nanocomposites have been prepared by the in situ reduction approach. The as-prepared hybrid materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The composition of the nanocomposites was fine tuned by varying the mass ratio of Au-to-CNTs. Among a series of samples tested, hybrid materials with a Au/carbon nanotubes (Au/CNTs) ratio = 1 : 2 demonstrated the best activity towards oxygen reduction reaction (ORR), as most positive onset potential, largest kinetic current density, highest amount of electron transfer and lowest H₂O₂ yields were obtained. Notably, the Au/CNTs also exhibited remarkable long-term durability higher than commercial Pt/C.