Surface terminations of hematite (α-Fe2O3) exposed to oxygen, hydrogen, or water: Dependence on the density functional theory methodology
Journal article, 2018

Hematite (α-Fe2O3) is the most stable and abundant iron oxide in nature, and is used in many important environmental and industrial technologies, such as waste-water treatment, gas sensors, and photoelectrocatalysis. A clear understanding of the structure, composition, and chemistry of the hematite surface is crucial for improving its function in these technologies. Here we employ density functional theory (DFT) together with the DFT+U approach using semi-local functionals, as well as hybrid functionals, to study the structure, stability, and electronic properties of the (0 0 0 1) surface exposed to oxygen, hydrogen, or water. The use of hybrid functionals allow for a description of strong correlation without the need for atom-specific empirical parameters (i.e. U). However, we find that PBE+U, and in part also PBE, give similar results as the hybrid functional HSE(12%) in terms of structure optimization. When it comes to stability, work function, as well as electronic structure, the results are sensitive to the choice of functionals, but we cannot judge which level of functional is most appropriate due to the lack of experimental observations.

surface stability

hybrid functional

DFT+U

DFT

hematite surface

Author

Baochang Wang

Chalmers, Physics, Chemical Physics

Anders Hellman

Chalmers, Physics, Chemical Physics

Journal of Physics Condensed Matter

0953-8984 (ISSN)

Vol. 30 27 275002

Subject Categories

Inorganic Chemistry

Other Chemistry Topics

Theoretical Chemistry

Areas of Advance

Nanoscience and Nanotechnology (SO 2010-2017, EI 2018-)

Energy

Materials Science

Infrastructure

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1088/1361-648X/aac743

More information

Latest update

7/27/2020