Features of hydrogen evolution during electrodeposition of loose deposits of copper, nickel and zinc

Features of hydrogen evolution during electrodeposition of dendritic copper, zinc and nickel deposits were studied in the present paper. Data on the changes in hydrogen current density and its differential current efficiency as well as porosity of copper, zinc and nickel deposits during electrolysis were obtained. It was shown that the potential during the formation of dendritic metal deposits is determined by the kinetic parameters of hydrogen reduction. Experimental data (the change in the electrode potential during electrodeposition and volume of evolved hydrogen) and hydrogen evolution kinetic parameters allowed to calculate the surface area available for hydrogen evolution during electrodeposition of loose metals. It was found that surface area available for hydrogen evolution increases during electrodeposition of loose metal under galvanostatic conditions. Morphology of dendrite particles and deposit growth rate are determined by metal nature, but properties of loose deposits (change in porosity along the deposit thickness) depend on the intensity of hydrogen evolution during electrolysis.