Au Nanoparticles Modified Co/Titania Nanotubes as Electrocatalysts for Borohydride Oxidation

Abstract

AbstractGold‐cobalt catalysts were deposited on the surface of titania nanotubes (TiO2‐NTs) via galvanic displacement technique. The catalysts were characterized using field emission scanning electron microscopy, energy dispersive X‐ray spectroscopy and inductively coupled plasma optical emission spectroscopy. The electrocatalytic activity of the Au(Co)/TiO2‐NTs catalysts was examined in respect to the oxidation of BH4− ions in an alkaline media by cyclic voltammetry and chronoamperometry. It was found that the Au(Co)/TiO2‐NTs catalysts with Au loadings in the range of 10 up to 59 µgAu cm−2 had a higher activity compared to that of Co/TiO2‐NTs and bare Au. A direct NaBH4‐H2O2 single fuel cell was constructed with the Au(Co)/TiO2‐NTs catalysts as anode and Pt as the cathode. The fuel cell exhibited an open circuit voltage of ca. 1.9 V and peak power densities up to 217 mW cm−2 at 25 °C. The highest specific peak power density of 16.3 kW g−1Au was obtained when employing Au(Co)/TiO2‐NTs with the Au loading of 10 µgAu cm−2 as the anode catalyst.