Effect of carbon content on Ni-Fe-C electrodes for hydrogen evolution reaction in seawater

Hydrogen evolution reaction (HER) on the Ni-Fe-C electrodes electrodeposited at current density ranging from 100 to 300 A/m(2), as well as their electrochemical properties in 3.5% NaCl solution at 90 degrees C and pH = 12, had been investigated by polarization measurements, EIS technique. It was shown that the carbon content and grain size of Ni-Fe-C coatings are affected by current density. In addition, the hydrogen evolution overpotential of Ni-Fe-C electrodes was related with carbon content and grain size. The Ni-Fe-C electrodes with optimum catalytic activity for the HER were found to contain the maximum carbon content 1.59% and the minimum grain size 3.4 nm. The results of a comparative analysis between carbon content and intrinsic activity are that carbon content plays an important role in intrinsic activity of Ni-Fe-C electrodes. Crown Copyright (C) 2010 Published by Elsevier Ltd on behalf of Professor T. Nejat Veziroglu. All rights reserved.