Nickel particles supported on multi-walled carbon nanotubes modified sponge for sodium borohydride electrooxidation

A novel Ni electrode with a unique three-dimensional hierarchical macro-porous structure is prepared by electrodeposition of spherical Ni particles onto multi-walled carbon nanotubes (MWNTs) which are assembled on the skeleton of a sponge. The morphology and phase structure of the Ni@MWNTs/Sponge electrode are characterized by a scanning electron microscope, transmission electron microscope and X-ray diffraction spectrometer. The catalytic performance of the Ni@MWNTs/Sponge electrode for NaBH4 electrooxidation is investigated by means of cyclic voltammetry and chronoamperometry. Results show that the Ni@MWNTs/Sponge electrode exhibits a remarkably high catalytic activity and good stability for NaBH4 electrooxidation. The oxidation current density reaches as high as 300 mA cm(-2) at -0.7 V in 2.0 mol dm(-3) NaOH and 0.1 mol dm(-3) NaBH4, which is significantly higher than that reported for other types of Ni electrodes. (C) 2013 Elsevier B.V. All rights reserved.