Effect of electrodeposition parameters and surface pretreatment on the electrochemical hydrogen production using nickel-plated stainless steel electrodes

In this work, the effect of time, potential and concentration of Ni2+ on the amount of nickel deposited during the preparation of nickeled electrodes by electrodeposition, as well as on the concentration of hydrogen produced by electrolysis using such electrodes, was analyzed. Untreated and sandblasted AISI/SAE 304 stainless steel expanded meshes were used as support. The reduction potential of the Ni2+/Ni-0 in the Watts bath was determined by cyclic voltammetry (CV) at 0.70 V vs. Ag/AgCl. Three-level full factorial design (3(3)) was employed to analyze principal effects and interactions between the electrodeposition parameters on the weight of nickel coating. The highest weight of nickel coating (0.41 g) was obtained at 2.3 V for 20 min, from 1.466 M Ni2+ Watts bath. Hydrogen production was evaluated by micro-electrolysis and macro-electrolysis studies. Three-level full factorial design (3(3)) was employed to analyze principal effects and interactions between the electrodeposition parameters on the amount of hydrogen produced. The highest amount of hydrogen produced (2530.5 mu mol), at 2.0 V after 30 min, was obtained with the as-prepared electrode with the highest weight of nickel coating. Morphologic and elemental analyses of this electrode by field emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (FESEM EDS) showed a coating with a rough surface formed by coarse grains, having a thickness of 46.92 mu m and a nickel composition of 99.29 at.%. (c) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study analyzed the effects of time, potential, and Ni2+ concentration on the amount of nickel deposited and hydrogen produced during electrodeposition and electrolysis using nickeled electrodes. The highest weight of nickel coating and hydrogen production were achieved under specific conditions, with morphological and elemental analyses revealing key characteristics of the electrodes.