NiFeZn codeposit as a cathode material for the production of hydrogen by water electrolysis

This work describes the development of a composite material, NiFeZn coatings, prepared from the electrodeposition of NiFeZn alloys followed by chemical leaching in KOH solution. A sulphate bath was used to electrodeposit the NiFeZn alloys (55, 1, 44% in atoms, respectively) on a mild steel substrate. The evaluation of this material as electrocatalyst for the hydrogen evolution reaction was carried out in alkaline solutions through steady-state polarization curves. The long term operation at 135 mA cm−2 showed good stability for up to 200 h. A positive aspect of this cathode is that the polarization behavior of the material shows one Tafel slope over the temperature range 25–80°C. The operational potential of this material in 28% KOH at 80°C is about 100 mV which is significantly lower than that of mild steel (400 mV).