Direct growth of 3D flower-like Pt nanostructures by a template-free electrochemical route as an efficient electrocatalyst for methanol oxidation reaction

In this paper, a facile electrochemical approach is reported towards the fabrication of Pt needle-like NFs (nanoflowers) at the surface of GCE (glassy carbon electrode). The morphology and composition of the Pt NFs are characterized by SEM (scanning electron microscopy) and EDS (energy dispersive spectroscopy), respectively. Taking methanol oxidation as a model reaction in an acid medium, the electrocatalytic performance of as-prepared Pt NFs has been evaluated by CV (cyclic voltammetry), chronoamperometry and EIS (electrochemical impedance spectroscopy) techniques. These 3D (three dimensional) NFs exhibit the excellent electrocatalytic activity and high level of poisoning tolerance to the carbonaceous oxidative intermediates for the electro-oxidation reaction in acidic media. In addition, EIS information discloses different impedance behaviors for methanol electrooxidation at various potentials on the Pt NFs catalyst and also the change of rate-determining step with increasing potential. The comparison of Pt NFs and Pt NPs (nanoparticles), prepared by electrodeposition in the presence of hydrogen bubbles, shows that the NFs catalyst has higher activity, better long-term stability and lowers Pt loading. The simplicity of method and quality of prepared surfaces suggest applications in catalysis where a convenient method to prepare Pt catalysts with high surface area in one step is desirable. (C) 2015 Elsevier Ltd. All rights reserved.