3-Dimensional Electrode Coatings Produced by Cold Spraying Process for Hydrogen Evolution

The aim of this work was to use cold sprayed nickel electrodes for high purity hydrogen production by alkaline water electrolysis. The hydrogen produced by this method could be used as a green and renewable energy resource. Three nickel coated electrodes were produced on aluminum substrates by the cold spraying process using different spraying parameters. To improve the energy efficiency of the water electrolysis process, triple phase boundaries were enhanced by increasing the electrocatalytic active surface area of the electrodes. This was achieved by development of ultrafine microstructures with large densities of grain boundaries at the top surface of the coatings. Influence of the spraying parameters on surface morphology, microstructure and electrocatalytic activity of the coatings was investigated. Electrocatalytic activity of the electrodes towards hydrogen evolution reaction (HER) was evaluated by analyzing their steady-state polarization curves and electrochemical impedance spectroscopy results.