Electrodeposition and characterization of nickel-copper alloy films as electrode material in alkaline media

A new and simple electrochemical procedure of anodic codeposition of nickel and copper oxide-hydroxide species on the gold electrode substrate from alkaline solutions is described. The electrodeposited alloy film, with an average composition Ni: Cu of 0.67 (i.e., Ni40Cu60) was investigated by electrochemical, scanning electron microscopy, and X-ray photoelectron spectroscopy techniques. The resulting deposited alloys appear uniform, smooth, adherent to the gold substrate, and homogeneous, independently of the electrochemical procedure adopted for the preparation (i.e., potentiostatic or potentiodynamic conditions). The presence of copper oxyhydroxide species in deposited film imparts an extensive stabilization of the beta/beta crystallographic forms of the nickel oxyhydroxide under prolonged repetitive potential cycling in alkaline medium. The electrocatalytic activity of the resulting composite Ni-Cu film was investigated toward the oxidation of carbohydrates using glucose as a model compound. (C) 2002 The Electrochemical Society.