Abstract In the work, the relative stability of the single substitutional defect MBi, single oxygen vacancy defect VO and the complex defect MBi-VO (M = Li, Na, K, Rb, Cs) in α -Bi2O3 as well as their influences on the electronic properties and optical absorption spectrum of α -Bi2O3 are investigated using hybrid density functional calculations. It is shown that the complex defect MBi-VO is easier to form than the single defect (MBi or VO). The calculated electronic structures and optical absorption spectrum for the supercell with complex defect are also closer to the available experimental data than these with the single defect. Further, the charge compensation effect in the M monodoped α -Bi2O3 case is supported. Particularly, the induced impurity level in the band gap by the single defect (MBi or VO) disappears when the complex defect MBi-VO is presented. This makes the possible recombination center of the photogenerated electrons and holes disappear. At the same time, the theoretical band gap in the complex defect case decreases, and the absorption capacity of the visible light enhances with increasing doping concentration. These calculations well understand the significant improvement of the photocatalytic activity in the visible light range for Na and Cs-doped α -Bi2O3 in very recent experiments. Besides, it could be a good strategy to effectively improve the visible light photocatalytic activity of α -Bi2O3, by preparing α -Bi2O3 with oxygen vacancies.

中文翻译：

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氧空位对 M (M=Li, Na, K, Rb, Cs) 掺杂 α-Bi2O3 中可见光光催化活性影响的混合密度泛函研究

摘要 研究了α-Bi2O3中单取代缺陷MBi、单氧空位缺陷VO和复合缺陷MBi-VO(M = Li, Na, K, Rb, Cs)的相对稳定性及其对使用混合密度泛函计算研究了 α -Bi2O3 的电子性质和光吸收光谱。结果表明，复合缺陷 MBi-VO 比单一缺陷（MBi 或 VO）更容易形成。具有复杂缺陷的超级电池的计算电子结构和光吸收光谱也比具有单一缺陷的超级电池更接近可用的实验数据。此外，支持 M 单掺杂 α -Bi2O3 情况下的电荷补偿效应。特别，当复合缺陷 MBi-VO 出现时，由单一缺陷（MBi 或 VO）引起的带隙中的诱导杂质能级消失。这使得光生电子和空穴的可能复合中心消失。同时，复杂缺陷情况下的理论带隙减小，可见光的吸收能力随着掺杂浓度的增加而增强。这些计算很好地理解了在最近的实验中，Na 和 Cs 掺杂的 α-Bi2O3 在可见光范围内的光催化活性的显着提高。此外，通过制备具有氧空位的α-Bi2O3，可以有效提高α-Bi2O3的可见光光催化活性。同时，复杂缺陷情况下的理论带隙减小，可见光的吸收能力随着掺杂浓度的增加而增强。这些计算很好地理解了在最近的实验中，Na 和 Cs 掺杂的 α-Bi2O3 在可见光范围内的光催化活性的显着提高。此外，通过制备具有氧空位的α-Bi2O3，可以有效提高α-Bi2O3的可见光光催化活性。同时，复杂缺陷情况下的理论带隙减小，可见光的吸收能力随着掺杂浓度的增加而增强。这些计算很好地理解了在最近的实验中，Na 和 Cs 掺杂的 α-Bi2O3 在可见光范围内的光催化活性的显着提高。此外，通过制备具有氧空位的α-Bi2O3，可以有效提高α-Bi2O3的可见光光催化活性。这些计算很好地理解了在最近的实验中，Na 和 Cs 掺杂的 α-Bi2O3 在可见光范围内的光催化活性的显着提高。此外，通过制备具有氧空位的α-Bi2O3，可以有效提高α-Bi2O3的可见光光催化活性。这些计算很好地理解了在最近的实验中，Na 和 Cs 掺杂的 α-Bi2O3 在可见光范围内的光催化活性的显着提高。此外，通过制备具有氧空位的α-Bi2O3，可以有效提高α-Bi2O3的可见光光催化活性。