Phase-Dependent Photocatalytic Ability of TiO2: A First-Principles Study

The electronic properties of defected TiO2 were investigated using the first-principles calculations based on density functional theory and generalized gradient approximation. Three typical defects, oxygen vacancy, titanium interstitial, and titanium vacancy, were considered in three TiO2 polymorphs...

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Bibliographic Details
Published in:Journal of chemical theory and computation 2009-11, Vol.5 (11), p.3074-3078
Main Authors: Pan, Hui, Gu, Baohua, Zhang, Zhenyu
Format: Article
Language:English
Subjects:
Condensed Matter, Interfaces, and Materials
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Summary:The electronic properties of defected TiO2 were investigated using the first-principles calculations based on density functional theory and generalized gradient approximation. Three typical defects, oxygen vacancy, titanium interstitial, and titanium vacancy, were considered in three TiO2 polymorphs, anatase, rutile, and brookite, respectively. Our calculations demonstrated that the defect band is formed by removing an oxygen atom from or inserting an interstitial Ti atom into the TiO2 lattice, which is responsible for the improvement of photocatalytic ability due to the enhanced visible-light absorption. Our calculations further revealed that the defect formation energy increases as following brookite, anatase, and rutile, indicating that defects are easy to be created in brookite TiO2. The relatively high defect density and wide defect band contribute to the better photocatalytic performance of brookite TiO2 in visible light.
ISSN:1549-9618
1549-9626
DOI:10.1021/ct9002724