Kinetic properties of the passive film on copper in the presence of sulfate-reducing bacteria

E. Huttunen-Saarivirta (Corresponding Author), E. Ghanbari, F. Mao, P. Rajala, L. Carpén, D. D. Macdonald

    Research output: Contribution to journalArticleScientificpeer-review

    5 Citations (Scopus)

    Abstract

    Copper specimens were exposed to Sulfate-Reducing Bacteria (SRB) for 10 months under the conditions corresponding to the final disposal of high-level nuclear waste. In-situ electrochemical impedance spectroscopy (EIS) measurements were carried out to characterize the surface-environment interface after various times of exposure. The EIS results are interpreted in terms of the Point Defect Model (PDM), in order to obtain kinetic information on the formation of the Cu2S passive film. The standard rate constant and the rate constants for the surface reactions revealed that the Cu2S layer is a p-type semiconductor. The diffusion constant for cation vacancies in the barrier layer and the average bulk cation vacancy concentration in the barrier layer were found to be on the orders of 10−13 cm2·s−1 and 1022 cm−3, respectively, i.e., both slightly higher than reported in literature for corresponding electrochemically developed Cu2S layers. The electric field strength was approximately 3·105 Vcm−1 at all measurement points. These results are presented and discussed in this work in the light of storage of high-level nuclear waste.

    Original languageEnglish
    Pages (from-to)C450-C460
    JournalJournal of the Electrochemical Society
    Volume165
    Issue number9
    DOIs
    Publication statusPublished - 1 Jan 2018
    MoE publication typeA1 Journal article-refereed

      Fingerprint

    Keywords

    • copper sulfide
    • passive film
    • point defect model

    Cite this