Band-to-band visible-light photon excitation and photoactivity induced by homogeneous nitrogen doping in layered titanates

Liu, Gang, Wang, Lianzhou, Sun, Chenghua, Yan, Xiaoxia, Wang, Xuewen, Chen, Zhigang, Smith, Sean C., Cheng, Hui-Ming and Lu, Gao Qing (2009) Band-to-band visible-light photon excitation and photoactivity induced by homogeneous nitrogen doping in layered titanates. Chemistry of Materials, 21 7: 1266-1274. doi:10.1021/cm802986r


Author Liu, Gang
Wang, Lianzhou
Sun, Chenghua
Yan, Xiaoxia
Wang, Xuewen
Chen, Zhigang
Smith, Sean C.
Cheng, Hui-Ming
Lu, Gao Qing
Title Band-to-band visible-light photon excitation and photoactivity induced by homogeneous nitrogen doping in layered titanates
Journal name Chemistry of Materials   Check publisher's open access policy
ISSN 0897-4756
Publication date 2009-03-10
Year available 2009
Sub-type Article (original research)
DOI 10.1021/cm802986r
Volume 21
Issue 7
Start page 1266
End page 1274
Total pages 9
Editor Interrante, L. V.
Place of publication Washington, D.C.
Publisher American Chemical Society
Collection year 2010
Language eng
Subject C1
090499 Chemical Engineering not elsewhere classified
850599 Renewable Energy not elsewhere classified
Abstract The distribution of dopants in semiconductors can intrinsically determine the electronic structure and consequently the absorbance, redox potential, and charge-carrier mobility of the semiconductor photocatalysts. In contrast to most reported nitrogen-doped titania photocatalysts with some localized states in the intrinsic band gap and small visible light absorption shoulders induced by inhomogeneous nitrogen doping near the particle surface, we report here the homogeneous substitution of O by N in the whole particles of layered titanates. The resultant materials Cs0.68Ti1.83O4-xNx exhibited extraordinary band-to-band excitation in the visible-light ranging up to blue light. From photoelectron spectroscopy and first-principles calculations, the upward shift of valence band maximum by N 2p states is concluded as the cause of the band-to-band visible light excitation. The holes generated upon visible light excitation in the newly formed valence bands Of Cs0.68Ti1.83O4-xNx and H0.68Ti1.83O4-xNx had strong oxidation ability in oxidizing OH- into active center dot OH radicals in photocatalysis. These findings are the clear evidence for the substantial role of homogeneous nitrogen doping in obtaining band-to-band visible-light photon excitation in layered titanates. The new physical insights into the electronic structure of homogeneous substitutional N in layered titanates gained here may have important implications for developing other efficient visible light photocatalysts by nonmetal doping.
Keyword Doped Titanium-dioxide
Sensitized Solar-cells
Photocatalytic H-2 Evolution
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Publication Date (Web): March 10, 2009

 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 144 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 148 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Fri, 09 Apr 2010, 09:55:54 EST by Vicki Thompson on behalf of Aust Institute for Bioengineering & Nanotechnology