Theoretical and experimental study of the interaction of O2 and H2O with metallic zinc-discussion of the initial step of oxide formation.

G. A. ALIMENTI; M. E.GSCHAIDER; J. C. BAZÁN; M. L. FERREIRA

JOURNAL OF COLLOID AND INTERFACE SCIENCE

Elsevier

Año: 2004 vol. 276 p. 24 - 38

0021-9797

The steps of Zn corrosion and ZnO formation using O2 dry or water/O2 atmospheres were investigated in situ using experimental and theoretical tools. The adsorption equilibrium and kinetics of O2/H2O on Zn have been measured at different temperatures and relative humidity using a Cahn 1000 Vacuum Recording Electrobalance. The adsorbed amounts on Zn are different in presence or absence of O2. SEM-EDAX, XPS and XRD studies have been performed at surface at different times of reaction. A theoretical study using the extended Hückel method has been done for the adsorption/reaction of H2O/O2 on Zn and on ZnO. A coherent explanation is presented for the initial steps of ZnO formation on Zn, for the steady state found for the ZnO growth and for the experimental findings of the methods cited above.