Predicting single-layer technetium dichalcogenides (TcX2, X = S, Se) with promising applications in photovoltaics and photocatalysis
Article
Article Title | Predicting single-layer technetium dichalcogenides (TcX2, X = S, Se) with promising applications in photovoltaics and photocatalysis |
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ERA Journal ID | 40638 |
Article Category | Article |
Authors | Jiao, Yalong (Author), Zhou, Liujiang (Author), Ma, Fengxian (Author), Gao, Guoping (Author), Kou, Liangzhi (Author), Bell, John (Author), Sanvito, Stefano (Author) and Du, Aijun (Author) |
Journal Title | ACS Applied Materials and Interfaces |
Journal Citation | 8 (8), pp. 5385-5392 |
Number of Pages | 8 |
Year | 2016 |
Publisher | American Chemical Society |
Place of Publication | United States |
ISSN | 1944-8244 |
1944-8252 | |
Digital Object Identifier (DOI) | https://doi.org/10.1021/acsami.5b12606 |
Web Address (URL) | https://pubs.acs.org/doi/abs/10.1021/acsami.5b12606 |
Abstract | One of the least known compounds among transition metal dichalcogenides (TMDCs) is the layered triclinic technetium dichalcogenides (TcX2, X = S, Se). In this work, we systematically study the structural, mechanical, electronic, and optical properties of TcS2 and TcSe2 monolayers based on density functional theory (DFT). We find that TcS2 and TcSe2 can be easily exfoliated in a monolayer form because their formation and cleavage energy are analogous to those of other experimentally realized TMDCs monolayer. By using a hybrid DFT functional, the TcS2 and TcSe2 monolayers are calculated to be indirect semiconductors with band gaps of 1.91 and 1.69 eV, respectively. However, bilayer TcS2 exhibits direct-bandgap character, and both TcS2 and TcSe2 monolayers can be tuned from semiconductor to metal under effective tensile/compressive strains. Calculations of visible light absorption indicate that 2D TcS2 and TcSe2 generally possess better capability of harvesting sunlight compared to single-layer MoS2 and ReSe2, implying their potential as excellent light-absorbers. Most interestingly, we have discovered that the TcSe2 monolayer is an excellent photocatalyst for splitting water into hydrogen due to the perfect fit of band edge positions with respect to the water reduction and oxidation potentials. Our predictions expand the two-dimensional (2D) family of TMDCs, and the remarkable electronic/optical properties of monolayer TcS2 and TcSe2 will place them among the most promising 2D TMDCs for renewable energy application in the future. |
Keywords | two-dimensional materials; technetium dichalcogenides; photovoltaics; photocatalysis; strain effect |
ANZSRC Field of Research 2020 | 400499. Chemical engineering not elsewhere classified |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions. |
Byline Affiliations | Queensland University of Technology |
University of Bremen, Germany | |
Trinity College, Ireland | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q5x34/predicting-single-layer-technetium-dichalcogenides-tcx2-x-s-se-with-promising-applications-in-photovoltaics-and-photocatalysis
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