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Engineering Isolated S Vacancies over 2D MoS2 Basal Planes for Catalytic Hydrogen Evolution.
- Source :
- ACS Applied Nano Materials; 3/25/2022, Vol. 5 Issue 3, p3521-3530, 10p
- Publication Year :
- 2022
-
Abstract
- The consensus has been built on the fact that the hydrogen evolution reaction (HER) activity of MoS<subscript>2</subscript> basal planes can be activated by S vacancies. Currently, the popular strategy for fabricating S vacancies is to remove part of S atoms of MoS<subscript>2</subscript>. Owing to the same identity of S atoms, the removal process is usually random and does not have selectivity. Herein, we develop a defect-predesigned strategy to produce MoS<subscript>2</subscript> with single-atomic S vacancies (SV-MoS<subscript>2</subscript>) simply by preparing Se-doped MoS<subscript>2</subscript> (Se-MoS<subscript>2</subscript>) and subsequent removing the Se of Se-MoS<subscript>2</subscript>. S vacancies originates from the vaporization of the doped Se atoms, making the formation of S vacancies have a high selectivity and raising a good possibility for precisely modulating the concentration of S vacancies. The results show that the concentration of S vacancies can be controlled over the range from ~7.46% to 13.54%. MoS<subscript>1.76</subscript> with ~12.10% of S vacancies exhibits outstanding HER performance: an overpotential of 100 mV at 10 mA cm<superscript>-2</superscript> and a Tafel slope of 49 mV dec<superscript>-1</superscript>, corroborating the theoretical prediction about the optimum concentration of S vacancies. Density functional theory calculation further reveals that the activation of MoS<subscript>2</subscript> basal planes may intrinsically originate from the modification of S vacancies to band structure and density of state of MoS<subscript>2</subscript>, optimizing the hydrogen adsorption energy. This defect-predesigned strategy reduces the probability of forming the aggregates of S vacancies and will be more helpful for understanding how S vacancies affect the properties of MoS<subscript>2</subscript>. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 25740970
- Volume :
- 5
- Issue :
- 3
- Database :
- Complementary Index
- Journal :
- ACS Applied Nano Materials
- Publication Type :
- Academic Journal
- Accession number :
- 156429603
- Full Text :
- https://doi.org/10.1021/acsanm.1c04151