高等学校化学学报 ›› 2025, Vol. 46 ›› Issue (2): 20240380.doi: 10.7503/cjcu20240380

• 物理化学 • 上一篇    下一篇

掺杂和点缺陷调控MoS2/ZnO异质结光解水性能的第一性原理研究

温俊青1(), 王嘉辉1, 张建民2   

  1. 1.西安石油大学理学院,西安 710065
    2.陕西师范大学物理学与信息技术学院,西安 710062
  • 收稿日期:2024-08-05 出版日期:2025-02-10 发布日期:2024-10-28
  • 通讯作者: 温俊青 E-mail:wenjq2013@163.com
  • 基金资助:
    陕西省自然科学基金(2023-JC-YB-028);西安石油大学研究生创新和实践能力培养计划项目(YCS23113091)

First-principles Study of Doping and Point Defects Modulating the Photodissociative Water Properties of MoS2/ZnO Heterojunction

WEN Junqing1(), WANG Jiahui1, ZHANG Jianmin2   

  1. 1.School of Science,Xi’an Shiyou University,Xi’an 710065,China
    2.School of Physics and Information Technology,Shaanxi Normal University,Xi’an 710062,China
  • Received:2024-08-05 Online:2025-02-10 Published:2024-10-28
  • Contact: WEN Junqing E-mail:wenjq2013@163.com
  • Supported by:
    the Natural Science Foundation of Shaanxi Province, China(2023-JC-YB-028);the Xi'an Shiyou University Postgraduate Innovation and Practical Ability Cultivation Program Project, China(YCS23113091)

摘要:

采用第一性原理计算方法研究了C, Pd元素掺杂及点缺陷MoS2/ZnO异质结的电子结构、 光学性质及光催化性能. 计算结果表明, 本征MoS2/ZnO异质结具有0.66 eV的直接带隙, 带边位置呈现Ⅱ型能带排列. 掺杂和缺陷可以有效减小MoS2/ZnO异质结的带隙, Pd@Zn为磁性半导体, VMo和VZn体系具有磁性半金属特性. 掺杂和缺陷使MoS2/ZnO异质结禁带之中出现杂质能级, 有利于电子跃迁, 吸收范围扩展至红外波段, 在可见光范围(500~760 nm)内的光吸收系数提高. 本征、 掺杂与缺陷MoS2/ZnO异质结体系界面处均存在由ZnO层指向MoS2层的内建电场, 促使本征MoS2/ZnO异质结, C@S2, Pd@Zn, VS1, VS2和VO体系形成直接Z型异质结, 促进了光生电子-空穴对的有效分离. 异质结的带边电位跨过pH=0和7时的氧化还原电位, 表明这些异质结可以在强酸溶液与中性溶液条件下进行氧化还原反应, 且载流子具有较强的氧化还原能力. 研究结果为基于MoS2/ZnO异质结的设计提供了理论参考.

关键词: MoS2/ZnO异质结, 掺杂缺陷, 电子结构, 光催化性能

Abstract:

The electronic structures, optical properties and photocatalytic performance of MoS2/ZnO heterojunction doping with C and Pd elements and point defects were studied using first principles calculations. The stable sites of C and Pd atom doping MoS2/ZnO heterojunction is S2 and Zn site, and the stable defect point is Zn defect. The analysis of electronic structures shows that band edge position of the intrinsic MoS2/ZnO presents a type II band alignments with a direct band gap of 0.66 eV. Doping and defects can effectively regulate the band gap of MoS2/ZnO. Pd@Zn system exhibits magnetic semiconductor, VMo and VZn systems exhibit magnetic metallic properties. Doping and defects increase the light absorption coefficient of MoS2/ZnO heterojunction in the visible light range(500—760 nm). Intrinsically, there is a built-in electric field from ZnO layer to MoS2 layer at the interface in the doping and defective MoS2/ZnO, which promotes charge transfer from ZnO layer to MoS2 layer. The charge transfer amount of Pd@Zn, C@S2&Pd@Zn increases. The intrinsic MoS2/ZnO, C@S2, Pd@Zn, VS1, VS2 and VO systems form direct Z-type heterojunctions, which promote the effective separation of photo generated electron hole pairs. The band edge potential of MoS2/ZnO, C@S2, Pd@Zn, VS1, VS2 and VO crosses the oxidation-reduction potential at pH=0 and 7, indicating that these heterojunctions can undergo oxidation-reduction reactions under strong acid solution and neutral solution conditions, and the carriers have strong oxidation-reduction ability.

Key words: MoS2/ZnO heterojunction, Doping and defect, Electronic structure, Photocatalytic property

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