有缺陷的层状MoS2复合TiO2的光催化机理

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文章编号： 16726987（2018）02005006； DOI： 10.16351/j.16726987.2018.02.008

郭凤娟， 高洪涛*

(青岛科技大学 化学与分子工程学院，山东 青岛 266042)

摘要： 采用第一性原理方法研究与有缺陷的层状MoS2(dMoS2)复合后TiO2的光催化性能增强的机理。结果发现，复合后体系更趋稳定。对TiO2/dMoS2两相界面处的态密度和电荷差分密度进行分析，结果表明：复合后最低未占据分子轨道（LUMO）均由Mo4d轨道组成，最高占据分子轨道（HOMO）主要由S3p、O2p轨道组成，电子由HOMO向LUMO跃迁。在光照射时，电子由TiO2迁移到dMoS2，在界面处的dMoS2侧累积了多余的电子。电子在TiO2与dMoS2之间的转移导致在界面间形成一个内极化电场，dMoS2的高电子传输性能使载流子很容易迁移，导致了光生电子和空穴的有效分离，有利于光催化性能的提高。

关键词： 第一性原理； 缺陷； TiO2/dMoS2； 电荷迁移； 光催化机理

中图分类号： O 649.4文献标志码： A

引用格式：郭凤娟， 高洪涛. 有缺陷的层状MoS2复合TiO2的光催化机理\[J\]. 青岛科技大学学报（自然科学版）， 2018， 39（2）： 5055.

GUO Fengjuan, GAO Hongtao. Investigation on enhanced photocatalytic mechanism of TiO2 by combined with defective layered MoS2\[J\]. Journal of Qingdao University of Science and Technology（Natural Science Edition), 2018, 39(2)： 5055.

Investigation on Enhanced Photocatalytic Mechanism of TiO2 by

Combined with Defective Layered MoS2

GUO Fengjuan, GAO Hongtao

 (College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology，Qingdao 266042, China)

Abstract: In this paper, FirstPrinciples calculation based on density functional theory (DFT) was used to determinate the enhanced photocatalytic mechanism of TiO2 by combinning with the defective layered MoS2 (dMoS2). The geometry structure and electronic properties, such as density of states, 3D charge density difference, have been investigated. And it revealed that TiO2/dMoS2 composites could be stable in thermodynamics. Theoretical calculations showed that the lowest unoccupied molecular orbital (LUMO) of the composite was mainly composed of Mo4d orbital, and the highest occupied molecular orbital (HOMO) was mainly composed of S3p, O2p orbital. The electrons transit from HOMO to LUMO easily. Electrons migrated from TiO2 to dMoS2 under irradiation, causing the electrons accumulated near the dMoS2 side. There appeared an internal polarized electric field, caused by the electrons transfer at the interface between TiO2 and dMoS2. Additionally, the high electrons transport capability of dMoS2 made carriers migrate with ease, resulting in efficient separation of photogenerated electrons and holes, which was favorable to the improvement of photocatalytic performance.

Key words: firstpriciples； defect; TiO2/dMoS2； charge transfer； photocatalytic mechanism

收稿日期：  20161211

基金项目： 国家自然科学基金项目(41573103).

作者简介： 郭凤娟（1990—），女，硕士研究生.*通信联系人.