Abstract First-principles calculations are used to explore the interfacial structures and photocatalytic mechanisms of the BiOI/Bi2MoO6 and BiOCl/Bi2MoO6 heterostructures. We find that both the BiOI/Bi2MoO6 and BiOCl/Bi2MoO6 composites have small lattice mismatch and good stability. The DOS analysis show that the BiOI/Bi2MoO6 belongs to type-II heterostructure, while the BiOCl/Bi2MoO6 composite is a type-I heterostructure. The analyses of the electron difference density and Mulliken charge suggest that charge transferring and redistribution occurs at the interfaces. Moreover, a built-in electric field directed from Bi2MoO6 to BiOI or BiOCl can be formed at the interfaces of the heterostructures. The band alignment and built-in electric field in the BiOI/Bi2MoO6 and BiOCl/Bi2MoO6 heterostructures can promote the separation of the photo-generated carriers, resulting in their improved photocatalytic activities compared with the single component. Our work may provide useful information for understanding the photocatalytic mechanisms of the BiOI/Bi2MoO6 and BiOCl/Bi2MoO6 heterostructures and developing more efficient heterostructure photocatalysts.

中文翻译：

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了解 BiOI/Bi2MoO6 和 BiOCl/Bi2MoO6 异质结构的光催化机制：第一性原理研究

摘要 利用第一性原理计算探索了BiOI/Bi2MoO6和BiOCl/Bi2MoO6异质结构的界面结构和光催化机理。我们发现 BiOI/Bi2MoO6 和 BiOCl/Bi2MoO6 复合材料都具有小的晶格失配和良好的稳定性。DOS分析表明BiOI/Bi2MoO6属于II型异质结构，而BiOCl/Bi2MoO6复合材料属于I型异质结构。电子差密度和马利肯电荷的分析表明电荷转移和重新分布发生在界面处。此外，可以在异质结构的界面处形成从 Bi2MoO6 到 BiOI 或 BiOCl 的内置电场。BiOI/Bi2MoO6 和 BiOCl/Bi2MoO6 异质结构中的能带排列和内置电场可以促进光生载流子的分离，与单一组分相比，提高了它们的光催化活性。我们的工作可能为理解 BiOI/Bi2MoO6 和 BiOCl/Bi2MoO6 异质结构的光催化机制和开发更有效的异质结构光催化剂提供有用的信息。