Electrocatalytic properties of a nickel–tantalum–carbon alloy in an acidic electrolyte

Amorphous films of mean composition Ni33Ta41C26 were prepared by deposition onto carbon paper using dc magnetron sputtering. The material showed low corrosion currents and significant electrocatalytic activity for hydrogen oxidation and oxygen reduction when polarised potentiostatically in 1.5 M H2SO4 at 20 and 70 °C. The results are interpreted in terms of the passivity of the tantalum component offering corrosion protection to the nickel electrocatalytic component in the aggressive acidic electrolyte.