1. The effect of surface orientation on band alignment and carrier transfer at WS2/CdS interface: Insight from first-principles calculations.
- Author
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Cheng, Kai, Wu, Peng, Hu, Wenbo, Wu, Lifan, Guo, Xu, Guo, Sandong, and Su, Yan
- Subjects
BINDING energy ,ELECTRON traps ,ENERGY bands ,CONSTRUCTION slabs ,SUBSTRATES (Materials science) ,HETEROSTRUCTURES - Abstract
Loading of WS
2 can greatly improve water splitting H2 generation efficiency of CdS in experiments. Here, we constructed WS2 /CdS(100) and WS2 /CdS(110) heterostructures with smaller mismatches and explored their interaction energy and band offset by first-principles calculations. Our calculation suggests that the WS2 /CdS(100) interface with a stronger binding energy is more active in experiments, while the WS2 /CdS(110) interface is metastable. The band alignment between CdS and WS2 is highly dependent on the orientation of the interfaces, and WS2 /CdS(100) and WS2 /CdS(110) belong to type-I and type-II band alignments, respectively. Therefore, a metal electrode and hole scavenger may be essential in experiments to help WS2 /CdS(100) efficiently trap electrons, and a suitable substrate and an appropriate growth temperature are also needed to composite the CdS(110) surface to achieve a higher photocatalytic efficiency. In addition, we performed a detailed analysis of the macroscopic average potential and found that the calculated accuracy of potential difference across the heterostructures due to slab thickness is less than 80 meV at WS2 /CdS interfaces. In total, our calculations not only explain the physical reasons for the increased efficiency of WS2 /CdS, but also provide a detailed guideline for the design of a more efficient synergistic catalyst. [ABSTRACT FROM AUTHOR]- Published
- 2024
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