Electrocatalytic activity of simple and modified Fe–P electrodeposits for hydrogen evolution from alkaline media

Electrodeposition of Fe–P, Fe–P–Pt and Fe–P–Ce into copper substrates is carried out under galvanostatic conditions. The influence of the current density on the composition of the deposits and the current efficiencies for the electrodeposition processes are determined. Preliminary data indicate that addition of formic acid to the electroplating bath improves the current efficiency for electrodeposition. Electrocatalytic activities of the heat-treated plated materials are investigated by dc polarisation and ac impedance techniques for the hydrogen evolution reaction (HER) in 1 M NaOH solution at 298 K. Steady-state polarisation curves and electrochemical impedance spectroscopy data show that improved catalytic activities for the HER are due to an increase in the effective surface area, a change in surface features upon heat treatment, the partial contribution of the Pt component, and the electrocatalytic synergism with Fe imposed by the Ce co-deposit. Cathodic potentiostatic measurements for medium time operation indicate that the electroplated materials are stable even in moderately aggressive alkaline solutions.

Research highlights
► Fe–P amorphous alloys have interesting properties, being possible candidates as electrocatalysts for the hydrogen evolution reaction (HER) and other complex electrochemical reactions.
► Some of those materials are prepared from novel electrolytic baths, and dc/ac methods are used for their characterisation towards the HER.