新型二维ZnO/InSe纳米复合材料电子结构与光催化性能的第一性原理研究

First-Principles Study on Electronic Structure and Photocatalytic Performance of a Novel Two-Dimensional ZnO/InSe Nanocomposite

基于密度泛函理论方法,系统研究了新型二维ZnO/InSe异质结的电子结构和光催化性能。计算结果表明,二维ZnO/InSe异质结的晶格失配率为3.3%,形成能为-2.43eV,表明异质结的结构稳定。异质结表现为Ⅱ型能带对齐,价带和导带的带偏置分别为0.51和1.34eV,能够有效降低电子和空穴的复合率,提高ZnO/InSe异质结的光催化性能。二维ZnO/InSe异质结是带隙值为2.23eV的直接带隙半导体材料,对应有良好的可见光吸收范围,且光吸收系数高达105 cm-1,能够进一步提升光吸收效率。此外,异质结的带边位置分别跨过水的氧化还原电位,可用于光解水制备氢气。因此,二维ZnO/InSe异质结是一种有前景的可见光光催化材料。

Based on the density functional theory method,electronic structure and photocatalytic performance of a novel two-dimensional ZnO/InSe heterostructure are systematically studied.The calculated results show that the lattice mismatch of the two-dimensional ZnO/InSe heterostructure is 3.3%,and the formation energy is-2.43 eV,indicating the structural stability of the heterostructure.The heterostructure exhibits type-Ⅱ band alignment.The band offsets of valence band and conduction band are 0.51 and 1.34 eV,respectively,which can effectively reduce the recombination of electrons and holes and improve the photocatalytic performance of a ZnO/InSe heterostructure.The heterostructure is a direct band gap semiconductor material with a band gap value of 2.23 eV,corresponding to a good visible-light absorption range,and the optical absorption coefficient up to 105cm-1,which can further improve the light absorption efficiency.Moreover,the band edge positions of the heterostructure straddle the water redox potentials,which can be used for overall water splitting.Hence,two-dimensional ZnO/InSe heterostructure is a promising visible light photocatalyst.