This thesis investigated the modification of nickel foam by electrodeposition of nickel
and nickel–iron alloy coatings for application in an alkaline electrolyzer. The aim of the
work was to examine the influence of constant-current and pulse electrodeposition on the
morphology, composition, and electrochemical response of the prepared electrodes.
Prior to deposition, the nickel foam was appropriately cleaned. Ni and Ni–Fe coatings
were then prepared from sulfate–chloride electrolytes. Different current regimes,
electrolyte concentrations, and pulse-deposition parameters were evaluated. Constant-
current deposition at 100 mA and pulse deposition at 100 mA with an on-time of 10 ms
and an off-time of 50 ms were selected for further experiments. Ni-coated electrodes were
used as cathodes, while Ni–Fe-coated electrodes were used as anodes.
The morphology of the coatings was examined using scanning electron microscopy, while
their elemental composition was determined by energy-dispersive X-ray spectroscopy.
The results showed that the electrodeposition conditions significantly affected the
coverage of the nickel foam, particle size and distribution, and preservation of the porous
substrate structure. At insufficient Ni²⁺ ion concentrations, a dark layer containing sulfur
and oxygen was formed; therefore, the electrolyte composition was adjusted for
subsequent experiments.
The prepared electrodes were tested in 6 M KOH using a two-electrode alkaline
electrolyzer. Polarization curves and apparent Tafel slopes were used to compare the
response of the entire electrolyzer cell. The work provides a basis for further optimization
of coating composition, electrodeposition conditions, and electrode stability during
alkaline water electrolysis.
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