Strain-Tunable Visible-Light-Responsive Photocatalytic Properties of Two-Dimensional CdS/g-C<sub>3</sub>N<sub>4</sub>: A Hybrid Density Functional Study
Guangzhao Wang,
Feng Zhou,
Binfang Yuan,
Shuyuan Xiao,
Anlong Kuang,
Mingmin Zhong,
Suihu Dang,
Xiaojiang Long,
Wanli Zhang
Affiliations
Guangzhao Wang
School of Electronic Information Engineering, Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing, Yangtze Normal University, Chongqing 408100, China
Feng Zhou
School of Electronic Information Engineering, Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing, Yangtze Normal University, Chongqing 408100, China
Binfang Yuan
School of Chemistry and Chemical Engineering, Yangtze Normal University, Chongqing 408100, China
Shuyuan Xiao
Institute for Advanced Study, Nanchang University, Nanchang 330031, China
Anlong Kuang
School of Physical Science and Technology, Southwest University, Chongqing 400715, China
Mingmin Zhong
School of Physical Science and Technology, Southwest University, Chongqing 400715, China
Suihu Dang
School of Electronic Information Engineering, Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing, Yangtze Normal University, Chongqing 408100, China
Xiaojiang Long
School of Electronic Information Engineering, Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing, Yangtze Normal University, Chongqing 408100, China
Wanli Zhang
School of Electronic Information Engineering, Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing, Yangtze Normal University, Chongqing 408100, China
By means of a hybrid density functional, we comprehensively investigate the energetic, electronic, optical properties, and band edge alignments of two-dimensional (2D) CdS/g-C 3 N 4 heterostructures by considering the effect of biaxial strain and pH value, so as to improve the photocatalytic activity. The results reveal that a CdS monolayer weakly contacts with g-C 3 N 4 , forming a type II van der Waals (vdW) heterostructure. The narrow bandgap makes CdS/g-C 3 N 4 suitable for absorbing visible light and the induced built-in electric field between the interface promotes the effective separation of photogenerated carriers. Through applying the biaxial strain, the interface adhesion energy, bandgap, and band edge positions, in contrast with water, redox levels of CdS/g-C 3 N 4 can be obviously adjusted. Especially, the pH of electrolyte also significantly influences the photocatalytic performance of CdS/g-C 3 N 4 . When pH is smaller than 6.5, the band edge alignments of CdS/g-C 3 N 4 are thermodynamically beneficial for oxygen and hydrogen generation. Our findings offer a theoretical basis to develop g-C 3 N 4 -based water-splitting photocatalysts.
