Composite-coating electrodes for hydrogen evolution reaction

The Ni, Co and Fe composite-coatings were prepared by electrolytic composite-deposition. The characterizations for the hydrogen evolution reaction (HER) were carried out in a 5 M KOH solution. Polarization and impedance measurements have shown that the composite-coating is catalytically more active than the Ni electrode. Overpotential on the Fe composite-coating electrode measured at 100 mA cm −2 are 250 mV less than that on the Ni electrode. ac impedance measurements indicate that high electrocatylitic activities on the composite-coating electrodes are resulted from larger real surface areas on the electrode.