First-Principles Calculations of Two-Dimensional CdO/HfS2 Van der Waals Heterostructure: Direct Z-Scheme Photocatalytic Water Splitting

Qiuhua Zhang; Kai Ren; Ruxing Zheng; Zhaoming Huang; Zongquan An; Zhen Cui

doi:10.3389/fchem.2022.879402

First-Principles Calculations of Two-Dimensional CdO/HfS2 Van der Waals Heterostructure: Direct Z-Scheme Photocatalytic Water Splitting

Front Chem. 2022 Apr 7:10:879402. doi: 10.3389/fchem.2022.879402. eCollection 2022.

Authors

Qiuhua Zhang¹, Kai Ren², Ruxing Zheng², Zhaoming Huang³, Zongquan An¹, Zhen Cui⁴

Affiliations

¹ School of Automobile and Aviation, Wuhu Institute of Technology, Wuhu, China.
² School of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing, China.
³ School of Mechanical Engineering, Wanjiang University of Technology, Ma'anshan, China.
⁴ School of Automation and Information Engineering, Xi'an University of Technology, Xi'an, China.

Abstract

Using two-dimensional (2D) heterostructure as photocatalyst for water splitting is a popular strategy for the generation of hydrogen. In this investigation, the first-principles calculations are explored to address the electronic performances of the 2D CdO/HfS₂ heterostructure formed by van der Waals (vdW) forces. The CdO/HfS₂ vdW heterostructure has a 1.19 eV indirect bandgap with type-II band alignment. Importantly, the CdO/HfS₂ vdW heterostructure possesses an intrinsic Z-scheme photocatalytic characteristic for water splitting by obtaining decent band edge positions. CdO donates 0.017 electrons to the HfS₂ layer in the heterostructure, inducing a potential drop to further separate the photogenerated electrons and holes across the interface. The CdO/HfS₂ vdW heterostructure also has excellent optical absorption capacity, showing a promising role as a photocatalyst to decompose the water.

Keywords: CdO/HfS2 heterostructure; Z-scheme; photocatalyst; two-dimensional; water splitting.