Mn-doped Ni(OH)2 Nanostructures as an Efficient Electrocatalyst for Methanol Oxidation in Basic Solution

Abstract

The Mn-doped Ni(OH)2 nanostructures were obtained by a simple ion-exchange hydrothermal method. The as-prepared materials were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDXS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) for their morphological, composition and structural properties. As a material for modified electrodes, electrochemical tests demonstrate that the methanol oxidation peak current density of Mn-doped Ni(OH)2 nanostructures reached 14.18 mA cm−2 at 0.596 V (vs Ag/AgCl) in NaOH electrolyte. Similarly, the Mn-doped Ni(OH)2 nanostructures also maintained good electrocatalytic stability during the term of 36,000 s. The improvement of electrochemical performance is related to the introduction of Mn element in Ni(OH)2. It may promote Ni in the Mn-doped Ni(OH)2 nanostructures to carry the lower electron density and the higher oxidation state which may be responsible for the better performance toward methanol oxidation.