In Situ XAFS Study of Oxides Formed on Nickel Thin Film Electrodes in KOHSolution

摘要

The composition and structure of the oxides formed on nickel are of greatinterest for a number of technological applications, e.g., batteries and corrosion. In spite of the considerable research that has been done, there is still much uncertainty as to the stoichiometry and structure of the various oxides (hydroxides) that are formed during the anodic oxidation of the nickel. This is due largely to the highly disordered or amorphous nature of the phases formed which makes structural determination by X-ray diffraction difficult. X-ray absorption Fine Structure (XAFS) spectroscopy is an excellent technique for the characterization of such materials which have no long range order. In this paper, we present initial results of an in situ study of the structure and composition of the oxides (hydroxides) formed on Ni thin film electrodes in 5M KOH solution as a function of the applied potential.