A new type of electrochemical formation of copper oxide during redox processes of the copper(II)-glycine complex at high pH

A new electrochemical preparation of a homogeneous film of cupric oxide has been proposed, which is achieved on an electrode by polarizing to a more positive potential than 0.5 V versus Ag \ AgCl in an alkaline solution containing Cu2+ and glycine. The Cu(II)-glycine complex is first electrooxidized to CuOH2+ and then this ion is reduced to copper oxide by the redox reaction with the oxidation of water. The constituent of the copper oxide was determined to be CuO from the EPMA and XRD results. FE-SEM observation of this oxide indicates that the leaf-shaped crystals spread vertically on the electrode surface. The redox behavior of a CuO-deposited ITO electrode in a solution with Fe(CN)(6)(4-) was quite similar to that on a naked ITO electrode, suggesting a relatively high conductive nature of the cupric oxide prepared from solution. (C) 2001 Elsevier Science B.V. All rights reserved.