LAUSR

Abstract 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+/Ni0 in the Watts bath was determined by cyclic voltammetry (CV) at 0.70 V vs. Ag/AgCl. Three-level full factorial design (33) 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 (33) 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 μmol), 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 μm and a nickel composition of 99.29 at.%.