Density functional theory study of atomic and electronic properties of defects in reduced anatase TiO2 nanocrystals

Kazuki Morita, Kenji Yasuoka

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Anatase TiO2 nanocrystals have received considerable attention owing to their promising applications in photocatalysis, photovoltaics, and fuel cells. Although experimental evidence has shown that the performance of nanocrystals can be significantly improved through reduction, the mechanistic basis of this enhancement remains unclear. To shed a light on the chemistry of reduced anatase TiO2 nanocrystals, density functional theory were used to investigate the properties of defects and excess electrons. We demonstrated that oxygen vacancies are stable both on the surface and at the sub-surface of the nanocrystal, while titanium interstitials prefer sub-surface sites. Different defect locations possessed different excess electron structures, which contributed to deep and shallow states in the band gap of the nanocrystals. Furthermore, valence band tailing was observed, resulting in band gap narrowing. The theoretical results presented here deepen our understanding, and show the potential of defects to considerably change the macroscopic properties of anatase TiO2 nanocrystals.

Original languageEnglish
Article number035119
JournalAIP Advances
Volume8
Issue number3
DOIs
Publication statusPublished - 2018 Mar 1

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anatase
nanocrystals
density functional theory
defects
electronics
photovoltaic cells
fuel cells
interstitials
electrons
titanium
chemistry
valence
augmentation
oxygen

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Density functional theory study of atomic and electronic properties of defects in reduced anatase TiO2 nanocrystals. / Morita, Kazuki; Yasuoka, Kenji.

In: AIP Advances, Vol. 8, No. 3, 035119, 01.03.2018.

Research output: Contribution to journalArticle

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