Hydrogen evolution reaction on NiCu electrodeposited electrodes in 6.0 M KOH

Abstract

This article presents research of the hydrogen evolution reaction on the NiCu electrodeposited electrodes in 6.0 M KOH solution. Alloy electrodes were deposited on copper substrate in solution containing citrate ions by potentiostatic technique. The influence of the alloying component on the catalytic activity of the electrodes was investigated by cyclicvoltametry (CV) and potentiostatic (PS) techniques. The results show that the hydrogen evolution reaction on the NiCu alloy electrodes in the alkaline solution occurred at voltage of ‐1 V/SCE with very low current density, and significantly increased only when the negative voltage was more negative than ‐1.3 V/SCE. The exchange current density iex decreased as the copper content in the alloy increased, but the rate decreased unevenly. At ‐1.6 V/SCE, the stabilized cathodic current density on the 58.3 % Cu electrode reached the highest value of about 40 mA/cm2, and is 2 to 3 times higher than that of Ni‐plated electrode.

Effect of stabilizing and brightening agents and some operated conditions on electroplating kinetics of NiCu alloys from citrate‐sulfate solutions

“…The original solution has a composition of 0.2 M sodium citrate and 30 g/L H3BO3, both acts as buffer and complexing agent with Cu 2+ and Ni 2+ ions. Based on our published work, [2] we have chosen the solution with concentration of Cu 2+ and Ni 2+ ions are 0.05 M and 0.5 M, respectively, to study the effect of the brighting agent and the effect of temperature, stirring speed on the cathode kinetics of alloy plating. Electrochemical polarization measurements were carried out in the electrode potential range from -0.8 to -1.2 V/SCE, with a scanning speed of 5 mV/s using the electrochemical workstation Biologic VSP300.…”

“…The co-deposited kinetics of Cu 2+ and Ni 2+ ions to form NiCu alloys in the solution containing citrate and ammonia complex have been studied. [1][2][3] Cu 2+ Cit complex ions react by two steps and are controlled by diffusion process. Ni 2+ ions react through two steps including the forming the Ni + intermediate adsorption form.…”

“…NiCu alloy plating can be applied as a metal corrosion protection coating or as an electrochemical catalyst electrode. [1][2][3][4] The ability to protect against to corrosion and the electrochemical catalytic activity of the alloy plating are highly dependent on the alloy composition and its surface morphology. The alloy with chemical composition and surface morphology appropriate can be fabricated by controlling solution composition and electrolyte operation.…”