Ab initio atomic thermodynamics investigation on oxygen defects in the anatase TiO2

Cheng, Zhijun and Liu, Tingyu and Yang, Chenxing and Gan, Haixiu and Chen, Jianyu and Zhang, Feiwu. 2013. Ab initio atomic thermodynamics investigation on oxygen defects in the anatase TiO2. Journal of Alloys and Compounds. 546: pp. 246-252.

Source Title

Journal of Alloys and Compounds

DOI

10.1016/j.jallcom.2012.08.036

ISSN

0925-8388

Remarks

NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Alloys and Compounds. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Alloys and Compounds, Vol. 546 (2013). DOI: 10.1016/j.jallcom.2012.08.036

URI

http://hdl.handle.net/20.500.11937/45335

Collection

Curtin Research Publications

Abstract

In the framework of the ab initio atomic thermodynamics, the preliminary analysis of the oxygen defectsin anatase TiO2 has been done by investigating the influence of the annealing treatment under representative conditions on three typical oxygen defects, that is, oxygen vacancy, oxygen adsorption and oxygen interstitial. Our results in this study agree well with the related experimental results. The molecular species of the adsorbed O2 is subject to the ratio of the number of the O2 to that of the vacancy, as well as to the initial orientation of O2 relative to the surface (101). Whatever the annealing condition is, the oxygen vacancy is easier to form at the surface than in the bulk indicating that the reduction reaction may firstly undertake at the surface during the annealing treatment, which is consistent with the phase transformation experiments. The molecular ion, peroxide species, caused by the interstitial oxygen has important contribution to the top of the valence band and lead to the reduction of the band gap.