Wang Guangzhao, Geng Lin, Tang Wenyi, Wang Biao, Zhao Wenxi, Zhang Wanli, Yuan Binfang, Yuan Hongkuan, Zhou Tingwei
School of Electronic Information Engineering, Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing, Yangtze Normal University, Chongqing 408100, People's Republic of China. Those authors contributed equally to this work.
Nanotechnology. 2020 Nov 27;31(48):485701. doi: 10.1088/1361-6528/abb15a.
The electronic structures of two dimensional (2D) CdS/ZnO heterostructure (CdZnHT) consisting of CdS singlelayer (SL) and ZnO SL are explored based on hybrid density functional calculation. The negative interface formation energies suggest the formation of CdZnHT is exothermic. The bandgap of CdZnHT is favorable for absorbing visible light, and the decent band edge position makes it thermodynamically feasible for spontaneous generation of oxygen and hydrogen. The formed electric field across the interface induced by charge transfer will reduce photogenerated carrier recombination and promote carrier migration. Particularly, CdZnHT is a type-II heterostructure. Oxygen generation takes place at ZnO layer and hydrogen production occurs at CdS layer, which will also promote the effective separation and migration of phogogenerated carriers and enhance photocatalytic performance. These findings suggest that 2D CdZnHTs are possible candidates as water-splitting photocatalysts.
基于杂化密度泛函计算，研究了由硫化镉单层（SL）和氧化锌SL组成的二维（2D）硫化镉/氧化锌异质结构（CdZnHT）的电子结构。负的界面形成能表明CdZnHT的形成是放热的。CdZnHT的带隙有利于吸收可见光，合适的带边位置使其在热力学上自发产生氧气和氢气成为可能。由电荷转移在界面处形成的电场将减少光生载流子的复合并促进载流子迁移。特别地，CdZnHT是一种II型异质结构。氧气在氧化锌层产生，氢气在硫化镉层产生，这也将促进光生载流子的有效分离和迁移并提高光催化性能。这些发现表明二维CdZnHTs有可能作为光解水催化剂。
