XPS and voltammetric studies on Ni1-xCuxCo2O4 spinel oxide electrodes

Spinel oxide electrodes of Ni1-xCuxCo2O4 (0.00 less than or equal to x less than or equal to 0.75) layers were prepared by thermal decomposition of the corresponding nitrate solutions on Ni mesh at 350 degrees C. The surface analysis was carried out by XPS and shows that the oxide's surface is rich in copper for all the studied compositions, and when x less than or equal to 0.10 an enrichment in nickel was also observed. The surface electrochemical properties were studied by cyclic voltammetry and correlated with XPS data. (C) 1998 Elsevier Science S.A. All rights reserved.