Effect of Substrate Material on the Electrodeposition of Porous Nickel Deposits onto Cylindrical Electrodes and Their Electrochemical Properties

Abstract

The effects of substrate material on the morphology and electrocatalytic properties of porous nickel foam electrodeposited from chloride solutions onto cylindrical electrodes made of copper, nickel, carbon steel, stainless steel, and zinc-coated aluminum are examined. The substrate material affects the number and size of macropores, porosity, the morphology of the dendrites forming the pore walls, and the specific surface area of the porous nickel electrodeposit (foam). Morphological differences between foams deposited on different substrates affect the electrocatalytic activity of foams in the hydrogen evolution reaction in an alkaline medium. The electrochemical properties of the foams are estimated by measuring hydrogen evolution depolarization relative to a smooth nickel electrode. Due to their high porosity, foams deposited on nickel substrates demonstrate high electrocatalytic activity. Lower porosity and activity are typical of deposits on copper and carbon steel substrates. The lowest porosity occurs on stainless steel and aluminum substrates, where adhesion of the nickel foam is also poor.