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

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.