摘要
Transition metal dichalcogenides are interesting candidates as photocatalysts for hydrogen evolution reaction.The MnPSe_(3)/WS_(2) heterostructure is hence studied here with first principles calculations by exploring its electronic properties under the application of an electric field.It is discovered that the band gap will decrease from the WS_(2) monolayer to the MnPSe_(3)/WS_(2) heterostructure with Perdew-Burke-Ernzerhof functional,while increase slightly when electron correlation is involved.The conduction band minimum of the heterostructure is determined by the MnPSe3 layer,while the valence band maximum is contributed by the WS_(2)layer.The band edges and band gap suggest that the heterostructure will have good photocatalytic properties for water splitting.Moreover,comparing to monolayer WS_(2),the light absorption in both the ultraviolet and visible regions will be enhanced.When an electric field is present,a linear relation is observed between the electric field and the band gap within specific range,which can thus modulate the photocatalytic performance of this heterostructure.
过渡金属硫属化合物是光催化分解水制氢的可能催化剂。在本工作中我们通过第一性原理计算研究了一个锰磷硒单层薄膜和二硫化钨单层薄膜所构成的异质结的电子结构性质,及其对外加电场的响应。我们发现构建异质结之后,体系的带隙比单层二硫化钨薄膜有所减小,其价带和导带的带隙边缘分别源自锰磷硒单层薄膜和二硫化钨单层薄膜。体系带隙的大小以及带隙边缘的位置表面该异质结可能是光催化分解水的良好催化材料。与单层二硫化钨薄膜相比较,所构建的异质结在紫外光和可见光区域对光的吸收都有所增强。在具有外加电场的情况下,在特定电场强度范围内电场强度和带隙存在线性关系,所以,施加外加电场可以有效地调节该异质结的带隙和带隙边缘位置,进而提升其催化性能。
作者
FANG Li-mei
ZENG Ying
EKHOLM Marcus
HU Chun-feng
FENG Qing-guo
方丽梅;曾迎;EKHOLM Marcus;胡春峰;冯庆国(Key Laboratory of Advanced Technologies of Materials,Ministry of Education,School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China;Department of Physics,Chemistry and Biology(IFM),Linkopings University,SE-58183 Linkoping,Sweden)
基金
Project(2682019CX06)supported by the Fundamental Research Funds for the Central Universities,China
Project(2019KY23)supported by Research Start-up Fund from the Southwest Jiaotong University,China
Projects(20ZDYF0236,20ZDYF0490)supported by the Key R&D Projects in the Field of High and new Technology of Sichuan,China
Project(52072311)supported by the National Natural Science Foundation of China
Project(2019JDJQ0009)supported by the Outstanding Young Scientific and Technical Talents in Sichuan Province,China。
