Comparison of Borohydride Oxidation on the Gold Crystallites Deposited on the Smooth and Fiber Cobalt Coatings

Abstract

In the present study the Co sublayers with different structures were used for the deposition of Au crystallites (denoted as Au(Co)/Ti). The smooth Co layer was deposited on the titanium surface via electroless deposition [1]. Cobalt coatings with a fiber structure were deposited from the electrolyte described in Ref. [2]. Au crystallites were deposited on the Co/Ti surface by immersion of Co/Ti into the 1 mM HAuCl4 + 0.1 M HCl solution at 25 oC for 0.5, 1 and 5 min, respectively [3]. The morphology, structure and composition of the prepared catalysts were examined by means of Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, X-ray diffraction and Inductively Coupled Plasma Optical Emission Spectroscopy. Electrocatalytic activity of the prepared catalysts was investigated towards the oxidation of borohydride by means of cyclic voltammetry and chronoamperometry.It was found that the gold particles deposited on the cobalt with a fiber and smooth structures show enhanced electrocatalytic activity towards the oxidation of borohydride in an alkaline medium as compared to that of bare Au and Co deposited on the Ti surface with smooth and fiber structures.