Liu Zuoyin, Kong Bo, Xu Xiang, Wang Wentao
School of Physics and Astronomy, China West Normal University, Nanchong 637002, China.
Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang, 550018, China.
Nanoscale. 2023 Nov 9;15(43):17555-17569. doi: 10.1039/d3nr04177h.
This study uses hybrid functional calculations to investigate the effects of various crystal facet combinations in BiOCl and BiOI on the photocatalytic activity of the BiOCl/BiOI heterostructure. The results show that the separation efficiencies of photo-generated electron-hole pairs in BiOCl(010)/BiOI(001) and BiOCl(010)/BiOI(010) are constrained by type I band alignments in principle. In contrast, BiOCl(001)/BiOI(001) and BiOCl(001)/BiOI(010) heterostructures, which operate under the direct Z-scheme type, exhibit an enhanced photo-generated charge separation efficiency, superior redox capacity, and enhanced visible light absorption. Specifically, BiOCl(001)/BiOI(010) exhibits a more remarkable reduction ability that can reduce O to ˙O. Furthermore, our investigations demonstrate that targeted I element doping in BiOCl(001)/BiOI(010) can reduce the band gap of the BiOCl(001) sheet, enhance visible light absorption, and maintain the direct Z-scheme characteristics, thereby further improving the photocatalytic performance. Additionally, we discovered that I doping can transform the BiOCl(010)/BiOI(001) heterostructure from type I into a direct Z-scheme heterostructure, resulting in a substantial enhancement in the separation efficiency and reduction ability of photo-generated carriers as well as visible light absorption with increasing I doping concentration. Considering the excellent charge injection efficiency observed in experiments with the BiOCl(010)/BiOI(001) heterostructure, I-BiOCl(010)/BiOI(001) may represent a superior photocatalyst. Thus, this study highlights the crucial and substantial roles of engineering specific crystal facet combinations and I doping in enhancing the photocatalytic performance of the BiOCl/BiOI heterostructure. This theoretical study contributes to the comprehension of related experimental findings and offers valuable insights for the development of novel BiOCl/BiOI heterostructures with superior photocatalytic activity.
本研究采用杂化泛函计算方法，研究了BiOCl和BiOI中各种晶面组合对BiOCl/BiOI异质结构光催化活性的影响。结果表明，BiOCl(010)/BiOI(001)和BiOCl(010)/BiOI(010)中光生电子-空穴对的分离效率原则上受I型能带排列的限制。相比之下，以直接Z-型机制运行的BiOCl(001)/BiOI(001)和BiOCl(001)/BiOI(010)异质结构表现出增强的光生电荷分离效率、优异的氧化还原能力和增强的可见光吸收。具体而言，BiOCl(001)/BiOI(010)表现出更显著的还原能力，能够将O还原为˙O。此外，我们的研究表明，在BiOCl(001)/BiOI(010)中进行靶向I元素掺杂可以降低BiOCl(001)片层的带隙，增强可见光吸收，并保持直接Z-型特征，从而进一步提高光催化性能。此外，我们发现I掺杂可以将BiOCl(010)/BiOI(001)异质结构从I型转变为直接Z-型异质结构，随着I掺杂浓度的增加，光生载流子的分离效率和还原能力以及可见光吸收都有显著提高。考虑到在BiOCl(010)/BiOI(001)异质结构实验中观察到的优异电荷注入效率，I-BiOCl(010)/BiOI(001)可能是一种优异的光催化剂。因此，本研究突出了设计特定晶面组合和I掺杂在提高BiOCl/BiOI异质结构光催化性能方面的关键和重要作用。这项理论研究有助于理解相关实验结果，并为开发具有优异光催化活性的新型BiOCl/BiOI异质结构提供有价值的见解。
