新型二维Zr2CO2/InS异质结可见光催化产氢性能的第一性原理研究

First-principles Study on the Photocatalytic Hydrogen Production of a Novel Two-dimensional Zr2CO2/InS Heterostructure

采用第一性原理计算方法,系统研究了新型二维Zr2CO2/InS异质结的电子结构和光催化性能。计算结果显示,二维Zr2CO2/InS异质结是一种直接带隙半导体材料,晶格失配率低于3%,形成能为–0.49 eV,说明其具有稳定的结构;Zr2CO2/InS异质结的带隙值为1.96 eV,对应较宽的可见光吸收范围,且吸收系数高达105 cm^–1;异质结表现出Ⅱ型能带对齐,价带和导带的带偏置分别为1.24和0.17 eV,表明光生电子从Zr2CO2层转移到InS层,而光生空穴则与之相反,从而实现了电子和空穴在空间上的有效分离。另外,InS是间接带隙半导体材料,能够进一步降低电子和空穴的复合率。综上所述,新型二维Zr2CO2/InS异质结是一种潜在的可见光光催化剂。

Electronic structure and photocatalytic performance of 2D novel Zr2CO2/InS heterostructure was systematically investigated using first principle calculations.The calculated results demonstrate that the Zr2CO2/InS heterostructure is a direct bandgap semiconductor with a lattice mismatch less than 3%and a formation energy of–0.49 eV,indicating a stable structure.Band gap of the Zr2CO2/InS heterostructure is 1.96 eV,which should have a wide visible light absorption range,and the absorption coefficient is up to 105 cm^–1.The heterostructure has a typical type-II band alignment,and its valence band and conduction band offsets are 1.24 and 0.17 eV,respectively,demonstrating the transfer of photo-generated electrons from Zr2CO2 layer to InS layer and vice versa for holes,which indicates that the electrons and holes can be separated effectively in space.In addition,InS is an indirect band gap semiconductor material,which can further reduce the recombination of electrons and holes.Therefore,the novel Zr2CO2/InS heterostructure is a potential visible-light photocatalyst.