A first-principles calculation on the electronic properties of Si/N-codoped TiO2

doi:10.1016/j.apsusc.2010.10.107

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	A first-principles calculation on the electronic properties of Si/N-codoped TiO2
	Shi, Weimei 1,3; Chen, Qifeng 2; Xu, Yao 1; Wu, Dong 1; Huo, Chunfang 1
刊名	APPLIED SURFACE SCIENCE
	2011-01-15
卷号	257 期号:7 页码:3000-3006
关键词	Si/n-codoping First-principles Electronic Properties
ISSN号	0169-4332
DOI	10.1016/j.apsusc.2010.10.107
英文摘要	To deeply understand the effects of Si/N-codoping on the electronic structures of TiO2 and confirm their photocatalytic performance, a comparison theoretical study of their energetic and electronic properties was carried out involving single N-doping, single Si-doping and three models of Si/N-codoping based on first-principles. As for N-doped TiO2, an isolated N 2p state locates above the top of valence band and mixes with O 2p states, resulting in band gap narrowing. However, the unoccupied N 2p state acts as electrons traps to promote the electron-hole recombination. Using Si-doping, the band gap has a decrease of 0.24 eV and the valence band broadens about 0.30 eV. These two factors cause a better performance of photocatalyst. The special Si/N-codoped TiO2 model with one O atom replaced by a N atom and its adjacent Ti atom replaced by a Si atom, has the smallest defect formation energy in three codoping models, suggesting the model is the most energetic favorable. The calculated energy results also indicate that the Si incorporation increases theNconcentration in Si/N-codoped TiO2. This model obtains the most narrowed band gap of 1.63 eV in comparison with the other two models. The dopant states hybridize with O 2p states, leading to the valence band broadening and then improving the mobility of photo-generated hole; the N 2p states are occupied simultaneously. The significantly narrowed band gap and the absence of recombination center can give a reasonable explanation for the high photocatalytic activity under visible light. (C) 2010 Elsevier B.V. All rights reserved.
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000285963200097
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/71583]
专题	中国科学院化学研究所
通讯作者	Xu, Yao
作者单位	1.Chinese Acad Sci, Inst Coal Chem, Key Lab Coal Convers, Taiyuan 030001, Shanxi, Peoples R China 2.Chinese Acad Sci, Inst Chem, CAS Key Lab Photochem, Beijing 100190, Peoples R China 3.Chinese Acad Sci, Grad Univ, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Shi, Weimei,Chen, Qifeng,Xu, Yao,et al. A first-principles calculation on the electronic properties of Si/N-codoped TiO2[J]. APPLIED SURFACE SCIENCE,2011,257(7):3000-3006.
APA	Shi, Weimei,Chen, Qifeng,Xu, Yao,Wu, Dong,&Huo, Chunfang.(2011).A first-principles calculation on the electronic properties of Si/N-codoped TiO2.APPLIED SURFACE SCIENCE,257(7),3000-3006.
MLA	Shi, Weimei,et al."A first-principles calculation on the electronic properties of Si/N-codoped TiO2".APPLIED SURFACE SCIENCE 257.7(2011):3000-3006.