Electro-oxidation of water on hematite: Effects of surface termination and oxygen vacancies investigated by first-principles
Artikel i vetenskaplig tidskrift, 2015

The oxygen evolution reaction on hydroxyl- and oxygen-terminated hematite was investigated using first-principle calculations within a theoretical electrochemical framework. Both pristine hematite and hematite containing oxygen vacancies were considered. The onset potential was determined to be 1.79 V and 2.09 V vs. the reversible hydrogen electrode (RHE) for the pristine hydroxyl- and oxygen-terminated hematite, respectively. The presence of oxygen vacancies in the hematite surface resulted in pronounced shifts of the onset potential to 3.09 V and 1.83 V. respectively. Electrochemical oxidation measurements conducted on thin-film hematite anodes, resulted in a measured onset potential of 1.66 V vs. RHE. Furthermore, the threshold potential between the hydroxyl- and oxygen-terminated hematite was determined as a function of pH. The results indicate that electrochemical water oxidation on hematite occurs on the oxygen-terminated hematite, containing oxygen vacancies.

Physics

ab-initio

photoelectrodes

Oxidation

augmented-wave method

generation

Water

oxide

transition

Chemistry

oxidation

Hematite

electrolysis

DFT

initio molecular-dynamics

Electrochemistry

energy

Författare

Anders Hellman

Chalmers, Teknisk fysik, Kemisk fysik

Kompetenscentrum katalys (KCK)

Beniamino Iandolo

Chalmers, Teknisk fysik, Kemisk fysik

Björn Wickman

Chalmers, Teknisk fysik, Kemisk fysik

Henrik Grönbeck

Chalmers, Teknisk fysik, Kemisk fysik

Kompetenscentrum katalys (KCK)

J. Baltrusaitis

Lehigh University

Surface Science

0039-6028 (ISSN)

Vol. 640 45-49

Ämneskategorier

Den kondenserade materiens fysik

DOI

10.1016/j.susc.2015.03.022