Electronic structures of relaxed BiOX (X = F, Cl, Br, I) photocatalysts
Electronic structures of relaxed BiOX (X = F, Cl, Br, I) photocatalysts
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松弛 BiOX (X = F, Cl, Br, I) 光催化剂的电子结构
DOI：
10.1016/j.commatsci.2008.03.005
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发表时间：
2008-10-01
影响因子：
3.3
通讯作者：
Zhu, Qingshan
中科院分区：
文献类型：
--
作者：
Huang, Wen Lai;Zhu, Qingshan
对于光催化剂BiOX（X = F，Cl，Br，I），采用密度泛函理论（DFT）计算了Bi 5d态和未采用Bi 5d态时的电子结构. BiOF表现出直接带隙，而其他三个物种呈现间接的功能。考虑Bi 5d态后，能隙明显扩大，与实验结果更接近。跃迁位置几乎与Bi 5d态的掺入无关，导带底随X原子序数的增加而减小. O2p和Xnp（对于X = F，Cl，Br和I，n分别为2，3，4和5）态占主导地位，而Bi6p态对导带贡献最大.随着X原子序数的增加，价带中局域X np态的密度峰向价带顶移动，同时沿着价带宽度和导带宽度的变化.原子和键的布居，以及轨道密度的空间分布也进行了研究。(C)2008 Elsevier B.V.保留所有权利。
For photocatalysts BiOX (X = F, Cl, Br, I), the atomic sites have been relaxed and the electronic structures have been calculated via the density functional theory (DFT) with or without the adoption of Bi 5d states. BiOF exhibits a direct band gap while the other three species present the indirect feature. The consideration of Bi 5d states results in apparent expansion of the gaps, which are closer to the experimental results. The transition positions are almost independent of the incorporation of Bi 5d states, and the conduction-band bottom flattens with the increase in X atomic number. Both O 2p and X np (n = 2, 3, 4 and 5 for X = F, Cl, Br and I, respectively) states dominate the valence-bands while Bi 6p states contribute most to the conduction-bands. The density peak of the localized X np states in the valence-band shifts towards the valence-band top with the increasing X atomic number, along with certain changes in the valence and conduction bandwidths. Atomic and bond populations, as well as the spatial distribution of orbital density have also been investigated. (C) 2008 Elsevier B.V. All rights reserved.