1. First-Principles Investigation on the Tunable Electronic Structures and Photocatalytic Properties of AlN/Sc 2 CF 2 and GaN/Sc 2 CF 2 Heterostructures.
- Author
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Liu, Meiping, Lu, Yidan, Song, Jun, Ma, Benyuan, Qiu, Kangwen, Bai, Liuyang, Wang, Yinling, Chen, Yuanyuan, and Tang, Yong
- Subjects
BAND gaps ,GIBBS' free energy ,ELECTRONIC structure ,HETEROSTRUCTURES ,REDUCTION potential - Abstract
Heterostructure catalysts are highly anticipated in the field of photocatalytic water splitting. AlN/Sc
2 CF2 and GaN/Sc2 CF2 heterostructures are proposed in this work, and the electronic structures were revealed with the first-principles method to explore their photocatalytic properties for water splitting. The results found that the thermodynamically stable AlN/Sc2 CF2 and GaN/Sc2 CF2 heterostructures are indirect semiconductors with reduced band gaps of 1.75 eV and 1.84 eV, respectively. These two heterostructures have been confirmed to have type-Ⅰ band alignments, with both VBM and CBM contributed to by the Sc2 CF2 layer. AlN/Sc2 CF2 and GaN/Sc2 CF2 heterostructures exhibit the potential for photocatalytic water splitting as their VBM and CBM stride over the redox potential of water. Gibbs free energy changes in HER occurring on AlN/Sc2 CF2 and GaN/Sc2 CF2 heterostructures are as low as −0.31 eV and −0.59 eV, respectively. The Gibbs free energy change in HER on the AlN (GaN) layer is much lower than that on the Sc2 CF2 surface, owing to the stronger adsorption of H on AlN (GaN). The AlN/Sc2 CF2 and GaN/Sc2 CF2 heterostructures possess significant improvements in absorption range and intensity compared to monolayered AlN, GaN, and Sc2 CF2 . In addition, the band gaps, edge positions, and absorption properties of AlN/Sc2 CF2 and GaN/Sc2 CF2 heterostructures can be effectively tuned with strains. All the results indicate that AlN/Sc2 CF2 and GaN/Sc2 CF2 heterostructures are suitable catalysts for photocatalytic water splitting. [ABSTRACT FROM AUTHOR]- Published
- 2024
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