Properties of the BiVO<sub>4</sub> (010) surface in single crystals and epitaxially grown samples: A joint first-principles and experimental effort

ORAL

Abstract

As a prototypical oxide for water photocatalysis, BiVO4 has many advantageous optoelectronic properties, including strong absorption in the visible and a favorable band alignment with water. However, its use as a photo-absorber is limited by its inefficient charge dynamics, especially at interfaces. Here, we present an integrated experimental and computational study aimed at an atomistic understanding of the surface morphology and electronic properties of BiVO4 as a function of oxygen vacancy concentration.

We carried out first-principles calculations with Quantum Espresso (www.quantum-espresso.org/) and XPS/UPS measurements to obtain work functions and band alignments with vacuum. We show that oxygen vacancies at the surface behave differently from their bulk counterpart, in terms of formation energy and transport of small polarons. We also compare single-crystalline and epitaxially-grown samples, with focus on the relation among oxygen vacancies, electronic structure, and growth techniques. Finally, based on a combined study of measured and STM microscopy images, we propose how varying surface termination may help tune the photoelectrochemical performance of BiVO4.

*This work was supported by the National Science Foundation (NSF) through grant CHE-1764399.

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Presenters

  • Wennie Wang

    • University of Chicago
    • Pritzker School of Molecular Engineering, The University of Chicago

Authors

  • Wennie Wang

    • University of Chicago
    • Pritzker School of Molecular Engineering, The University of Chicago

  • Patrick Strohbeen

    • Materials Science and Engineering, University of Wisconsin Madison
    • Materials Science and Engineering, University of Wisconsin-Madison

  • Dongho Lee

    • Department of Chemistry, University of Wisconsin-Madison

  • Chenyu Zhou

    • Department of Chemical Engineering, Columbia University

  • Jason Kawasaki

    • Materials Science and Engineering, University of Wisconsin Madison
    • Materials Science, University of Wisconsin-Madison
    • Materials Science and Engineering, University of Wisconsin-Madison
    • Cornell University

  • Kyoung-Shin Choi

    • Department of Chemistry, University of Wisconsin-Madison

  • Mingzhao Liu

    • Center for Functional Nanomaterials, Brookhaven National Laboratory

  • Giulia Galli

    • University of Chicago
    • Pritzker School of Molecular Engineering, University of Chicago
    • Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
    • University of Chicago and Argonne National Laboratory
    • Pritzker School of Molecular Engineering, The University of Chicago