Electrocatalytic activity of the nanostructured Au–Co catalyst deposited onto titanium towards borohydride oxidation

•Deposition of Au–Co catalysts on Ti via electroless Co and galvanic displaced Au.•Characterization of the catalysts obtained by means of FESEM, EDAX, XRD and ICP-OES.•Enhanced activity of Au(Co)/Ti catalysts towards the oxidation of H2 and BH4−BH4− ions.•The long-term CVs show deactivation of Au(Co)/Ti catalysts.

The nanostructured gold–cobalt catalysts were deposited onto titanium surface via galvanic displacement technique. The electrocatalytic activity of the as-prepared nanostructured Au(Co)/Ti catalysts was examined in respect to the oxidation of BH4−BH4− ions in alkaline medium by using of the cyclic voltammetry and chrono-techniques. The nanostructured catalysts were prepared via galvanic displacement reactions between hierarchical Co thin films prepared by electroless deposition and a solution of HAuCl4. The surface morphology and composition of the samples were characterized using Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy and X-ray diffraction. The prepared nanostructured Au(Co)/Ti catalysts exhibit an enhanced electrochemical activity towards the electro-oxidation of H2 generated by catalytic sodium borohydride hydrolysis and oxidation of BH4−BH4− ions.