Catalysis on oxidized ferroelectric surfaces—Epitaxially strained LaTiO₂N and BaTiO₃ for photocatalytic water splitting

Vonrüti, Nathalie; Aschauer, Ulrich (2020). Catalysis on oxidized ferroelectric surfaces—Epitaxially strained LaTiO₂N and BaTiO₃ for photocatalytic water splitting. The Journal of Chemical Physics, 152(2), 024701. American Institute of Physics 10.1063/1.5135751

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Surface properties of ferroelectrics are promising for catalysis due to the spontaneous electric polarization that can be reversed by an applied electric field. While several theoretical studies show different catalytic activities for differently polarized ferroelectric surfaces at zero electric potential, little work was devoted to catalysis on ferroelectric surfaces at higher electric potentials. Under these conditions that are relevant for photocatalytic experiments and applications, surfaces are usually oxidized. Using density functional theory calculations, we show for LaTiO2N and BaTiO3 that this oxidation heavily impacts and even determines the electronic properties of the catalyst surface and therefore leads to similar reaction free energies for the catalytic steps of the oxygen evolution reaction, irrespective of the bulk polarization. This is opposed to experimental studies, which found different activities for differently polarized catalyst surface domains under oxidizing conditions. We therefore conclude that the experimentally observed activity difference does not originate from the surface polarization following the bulk polarization, but rather from different bulk polarization directions leading to different adsorbate coverages or even surface reconstructions.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Departement of Chemistry and Biochemistry

UniBE Contributor:

Vonrüti, Nathalie Simone and Aschauer, Ulrich Johannes

Subjects:

500 Science > 570 Life sciences; biology
500 Science > 540 Chemistry

ISSN:

0021-9606

Publisher:

American Institute of Physics

Language:

English

Submitter:

Ulrich Johannes Aschauer

Date Deposited:

23 Jan 2020 09:34

Last Modified:

26 Jan 2020 02:50

Publisher DOI:

10.1063/1.5135751

BORIS DOI:

10.7892/boris.138888

URI:

https://boris.unibe.ch/id/eprint/138888

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