| 摘要: |
| 基于电子密度泛函理论计算，系统研究了氧空位对V-C(p型)、Cr-N(n型)、V-N和Cr-C(电中性)四种共掺型锐钛矿TiO2的几何和电子结构的影响．结果表明在最稳定构型中氧空位处在与金属杂质原子相连的位置．由于氧空位的出现，共掺TiO2禁带中一些未占据的杂质态被填充满电子，掺杂体系的导带带边位置几乎不变，这有利于减少光生载流子复合，且不影响光解水过程中的产氢反应，在厌氧条件下很容易在V-N共掺TiO2中引入氧空位． |
| 关键词: TiO2 共掺杂 氧空位 电子结构 光电化学性质 |
| DOI：10.1063/1674-0068/28/cjcp1411196 |
| 分类号: |
| 基金项目: |
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| Impact of Oxygen Vacancy on Band Structure Engineering of n-p Codoped Anatase TiO2 |
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Qiang-qiang Meng1, Jia-jun Wang2, Jing Huang1,2,3, Qun-xiang Li1
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1.Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China;2.College of Chemistry, Tianjin Normal University, Tianjin 300387, China;3.School of Materials and Chemical Engineering, Anhui Jianzhu University, Hefei 230601, China
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| Abstract: |
| Doping with various impurities is an effective approach to improve the photoelectrochemical properties of TiO2. Here, we explore the effect of oxygen vacancy on geometric and electronic properties of compensated (i.e. V-N and Cr-C) and non-compensated (i.e. V-C and Cr-N) codoped anatase TiO2 by performing extensive density functional theory calculations. Theoretical results show that oxygen vacancy prefers to the neighboring site of metal dopant (i.e. V or Cr atom). After introduction of oxygen vacancy, the unoccupied impurity bands located within band gap of these codoped TiO2 will be filled with electrons, and the position of conduction band offset does not change obviously, which result in the reduction of photoinduced carrier recombination and the good performance for hydrogen production via water splitting. Moreover, we find that oxygen vacancy is easily introduced in V-N codoped TiO2 under O-poor condition. These theoretical insights are helpful for designing codoped TiO2 with high photoelectrochemical performance. |
| Key words: Oxygen vacancy Band structure engineering n-p codoped Anatase TiO2 |
