A joint theoretical and experimental study of the (Ni,Fe)-oxyhydroxide oxygen evolution catalyst for water splitting

ORAL

Abstract

Recent experiments showed that iron doped nickel oxyhydroxides are excellent catalysts for driving the oxygen evolution reaction (OER) of water splitting; however, the role played by iron is still controversial.[1, 2, 3] In a joint theoretical and experimental study, we investigated the optoelectronic properties and oxidation potentials of the (Ni,Fe)-oxyhydroxide layered materials, and we determined oxidation states, band gaps and analyzed the role of iron doping. We found that Fe(IV) is present in catalytically active, doped oxyhydroxides, consistent with the suggestions of recent in operando Mossbauer experiments,[3] and that oxygen atoms bound to the Fe dopants might be the most active sites for OER in oxyhydroxide films. We also showed that hybrid functionals give a more accurate account of the optical properties of these materials than the widely adopted DFT+U level of theory. [1] L. Trotochaud et al., JACS 136, 6744 (2014). [2] D. Friebel et al., JACS 137, 1305 (2015). [3] J. Y. C. Chen et al., JACS 137, 15090 (2015).

*This work was supported by NSF under the NSF center NSF-CHE-1305124.

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Authors

  • Zachary K. Goldsmith

    • Department of Chemistry, University of Illinois at Urbana-Champaign

  • Aparna K. Harshan

    • Department of Chemistry, University of Illinois at Urbana-Champaign

  • Marton Voros

    • Materials Science Division, Argonne Natl Lab
    • Argonne Natl. Lab
    • Argonne Natl Lab
    • Materials Science Division, Argonne National Laboratory

  • James Gerken

    • Department of Chemistry, University of Wisconsin-Madison

  • Shannon S. Stahl

    • Department of Chemistry, University of Wisconsin-Madison

  • Giulia Galli

    • Univ of Chicago and Argonne National Laboratory
    • Univ of Chicago
    • University of Chicago; Argonne National Laboratory
    • Institute for Molecular Engineering, University of Chicago; Argonne National Laboratory
    • Institute for Molecular Engineering, University of Chicago and Materials Science Division, Argonne Natl Lab
    • Institute for Molecular Engineering, University of Chicago; Materials Science Division, Argonne National Laboratory
    • Institute for Molecular Engineering, University of Chicago, Chicago, IL 60637 and Materials Science Division, Argonne National Laboratory, Lemont, IL
    • Institute for Molecular Engineering, University of Chicago and Argonne Natl Lab
    • University of Chicago, Chicago, IL 60637, USA
    • The University of Chicago, Institute for Molecular Engineering and Argonne National Laboratory
    • Argonne National Laboratory and University of Chicago
    • Institute for Molecular Engineering, University of Chicago and Materials Science Division, Argonne National Laboratory
    • University of Chicago
    • The University of Chicago
    • University of Chicago and Argonne National Laboratory

  • Sharon Hammes-Schiffer

    • Department of Chemistry, University of Illinois at Urbana-Champaign