Structural and electronic properties of oxygen defective and Se-doped p-type BiVO4(001) thin film for the applications of photocatalysis
Structural and electronic properties of oxygen defective and Se-doped p-type BiVO4(001) thin film for the applications of photocatalysis
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DOI：
10.1016/j.apcatb.2017.11.034
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发表时间：
2018-05-01
影响因子：
22.1
通讯作者：
Mallick, Tapas K.
中科院分区：
文献类型：
--
作者：
Ullah, Habib;Tahir, Asif A.;Mallick, Tapas K.
单斜晶 BiVO4 由于其稳定性、成本效益、易于合成和窄带隙而被用作光催化剂。尽管 BiVO4 的价带最大值 VBM（与真空下相似 -6.80 eV）远低于水的氧化还原电势，但其正导带最小值 CBM（与真空下 -4.56 eV）较小，这导致了其效率低下。我们对原始、缺氧 (O-v) 和 Se 掺杂的 BiVO4 进行了全面的周期密度泛函理论 (DFT) 模拟，不仅设计了其 CB 边缘位置，还设计了整体光催化和载流子特性。我们的理论方法很好地再现了原始 BiVO4 的实验数据，这鼓励我们进一步阐述其 0 和 Se 掺杂特性。研究发现，Ov（1％氧空位）和Se掺杂BiVO4（1-2％Se）都具有理想的带边、带隙以及较小的电子和空穴有效质量，具有较高的光催化活性。此外，Se掺杂的BiVO4表现为p型半导体。最后，所选表面的光催化水分解行为与水相互作用进行了反检验，其中大约-38至-50 kcal/mol的强水吸附能证实并预测了它们与母体BiVO4相比具有更高的效率。
Monoclinic BiVO4 is being used as a photocatalyst due to its stability, cost-effectiveness, ease of synthesis, and narrow band gap. Although, the valence band maximum, VBM (similar to -6.80 eV vs vacuum) of BiVO4 is well below the redox potential of water but having less positive conduction band minimum, CBM (-4.56 eV vs vacuum), responsible for its low efficiency. We have carried out a comprehensive periodic density functional theory (DFT) simulations for the pristine, Oxygen defective (O-v) and Se doped BiVO4, to engineer not only its CB edge position but the overall photocatalytic and charge carrier properties. Our theoretical method has nicely reproduced the experimental data of pristine BiVO4, which encouraged us to elaborate further its 0, and Se-doped characteristics. It is found that both the Ov (1% Oxygen vacancy) and Se-doped BiVO4 (1-2% Se) have ideal band edges, band gaps, and small effective masses of electrons and holes, responsible for high photocatalytic activities. Moreover, Se-doped BiVO4 behave as p-type semiconductor. Finally, the photocatalytic water-splitting behaviour of the selected surfaces were counterchecked with water interaction, where the strong water adsorption energy of about similar to -38 to -50 kcal/mol, confirms and predicts their higher efficiencies compared to that of parent BiVO4.