AUGER-ELECTRON SPECTROSCOPIC STUDY OF BINARY NICKEL(II)-IRON(III) HYDROXIDES

Surface analysis of coprecipitated binary Ni(II)-Fe(III) hydroxide solid solutions using Auger electron spectroscopy and depth profiling has revealed redistribution of the components (nickel and iron) within the surface layers showing significantly increased iron-to-nickel ratios, as compared to the corresponding gross averaged values in the bulk. The results are compared with transmission Mossbauer spectroscopic data obtained earlier for these systems, which are interpreted in terms of the presence of surface-related iron(III)-containing forms featured by essentially higher quadrupole splitting values. The surface analysis data presented are also discussed in connection with the high electrocatalytic activity of composite nickel-iron hydroxide systems towards anodic oxygen evolution in alkaline electrolytes revealed previously.