Electrocatalytic activation of Ni electrode for hydrogen production by electrodeposition of Co and V species

Hydrogen is considered to be the most promising candidate as a future energy carrier. One of the most used technologies for the electrolytic hydrogen production is alkaline water electrolysis. Electrode materials used in alkaline water electrolysis are mainly made from Ni or Ni-based alloys due to their desirable mechanical and chemical stability in hot and alkaline solution. Considerable research effort has been conducted on enhancement of electrocatalytic activity of Ni electrodes. Electrocatalytic activity of Ni electrode for the hydrogen evolution reaction (HER) in alkaline solution was compared to the electrode made from electrodeposition of Co and Co-V species on Ni support electrode using ac and dc electrochemical techniques. Analysis of Tafel polarization curves for the HER in alkaline solution reveals an increased electrocatalytic activity of the electrodeposited electrodes if compared to the Ni, This was additionally proved by measuring energy input (overpotential) for the given hydrogen production (fixed current density) and vice versa. Electrochemical impedance spectroscopy was applied in order to investigate the obtained effect of electrodeposited electrodes. It was found that the apparent electrochemical surface of investigated electrodes was significantly increased by the process of electrodeposition. (c) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.