Charge Trapping Process in Photoexcited Nitrogen-Doped Titanium Oxides.
Inorg Chem
; 59(15): 10439-10449, 2020 Aug 03.
Article
em En
| MEDLINE
| ID: mdl-32687701
We present a first-principles study on the structural changes induced by charge trapping that occurs after photoexcitation in nitrogen-doped titanium oxide (N-TiO2). The charge trapping site and the corresponding K edge EXAFS spectra of Ti atoms were predicted and compared with those obtained by an experiment under ultraviolet (UV) light excitation. The results indicate that charge trapping occurs in the neighborhood of the oxygen vacancy (O-vac) sites. Furthermore, our calculations show that the O-vac site significantly affects the EXAFS spectra, while substitutional nitrogen doping for an oxygen site in the vicinity of the O-vac site is insensitive in the EXAFS spectra. Based on this observation combined with the knowledge from previous experiments, we propose a charge trapping process where the UV light-excited electron migrates at the O-vac site in bulk (â¼300 ps) while the visible light-excited electron (N 2p â Ti 3d) is immediately trapped at the O-vac site neighboring the N site (â¼1 ps).
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Inorg Chem
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Japão