SiS_(2)/ZnO范德华异质结光催化水分解第一性原理研究  

First-principles study on the photocatalytic water splitting of SiS_(2)/ZnO van der Waals heterostructure

作　　者：李家豪 黄欣 杨志红[2] LI Jia-Hao;HUANG Xin;YANG Zhi-Hong(College of Electronic and Optical Engineering&College of Flexible Electronics(Future Technology),Nanjing University of Posts and Telecommunications,Nanjing 210023,China;College of Science,Nanjing University of Posts and Telecommunications,Nanjing 210023,China)

机构地区：[1]南京邮电大学电子与光学工程学院、柔性电子(未来技术)学院,南京210023 [2]南京邮电大学理学院,南京210023

出　　处：《原子与分子物理学报》2025年第6期31-36,共6页Journal of Atomic and Molecular Physics

摘　　要：基于第一性原理方法,研究了SiS_(2)/ZnO范德华异质结的电子结构和光催化性质.结果表明,SiS_(2)/ZnO异质结是带隙值为1.32 eV的半导体材料,表现出交错排列的能带结构.在异质结界面处,形成了从ZnO指向SiS_(2)的内置电场,该内置电场的存在使得SiS_(2)/ZnO异质结中形成了特殊的“Z-型”载流子迁移模式,有利于电子空穴对的有效分离,同时增强了载流子的氧化还原能力.异质结构具有良好的热力学稳定性,且带边位置跨越水的氧化还原电位.与单层材料相比,SiS_(2)/ZnO异质结光吸收谱出现红移现象,表现出更宽的光吸收范围(从可见光到紫外光)及更强的光吸收强度(达到10~5 cm^(-1)量级).另外,通过施加双轴应变,可以有效调控SiS_(2)/ZnO异质结的带隙值.以上结果表明SiS_(2)/ZnO异质结有潜力成为新型光催化剂用于全解水.Based on the first-principles method,the electronic structure and photocatalytic properties of the SiS_(2)/ZnO van der Waals heterostructure have been studied.The results indicate that the SiS_(2)/ZnO heterostructure is a semiconductor material with a bandgap value of 1.32 eV,exhibiting a staggered band structure.At the interface of the heterostructure,an internal electric field pointing from ZnO to SiS_(2)is formed.The presence of this internal electric field results in a special"Z-scheme"carrier migration mode in the SiS_(2)/ZnO heterostructure,which is beneficial for the effective separation of electron-hole pairs and enhancing redox capabilities of the carriers.The SiS_(2)/ZnO heterostructure exhibits good thermodynamic stability,and its band edge positions span the redox potential of water.Compared to the monolayer materials,the optical absorption spectrum of the SiS_(2)/ZnO heterostructure exhibits a red shift,demonstrating a broader range of light absorption(from visible light to ultraviolet light)and stronger light absorption intensity(reaching the order of 10^(5)cm^(-1)).Additionally,the bandgap value of the SiS_(2)/ZnO heterostructure can be effectively modulated by applying biaxial strain.The above results indicate that the SiS_(2)/ZnO heterostructure has the potential to become a novel photocatalyst for overall water splitting.

关 键 词：SiS_(2)/ZnO Z-型范德华异质结 光催化 电子结构 第一性原理 

分 类 号：O469[理学—凝聚态物理]