Abstract
Sulfur (S) vacancies in MoS2 have been found to act as a new active center, which shows an unprecedented intrinsic HER activity under elastic strain. However, such S-vacancies are unstable and the activities are very sensitive to the vacancy concentration. A strategy to stabilize these abundant active sites is thus highly desirable. Herein, we rationally design a catalyst system to stabilize S-vacancies in the basal plane of 2H-MoS2 supported on defective vertical graphene network (VGN). The energetically favorable line-shaped S-vacancies in MoS2 show a consistently high HER activity that is insensitive to S-vacancy concentration. Moreover, the defective graphene support effectively stabilizes these S-vacancies. The optimized catalyst exhibits a superior HER activity with overpotential of 128 mV at 10 mA cm-2 and Tafel slope of 50 mV dec-1. Most importantly, the catalyst shows greatly increased stability over 500 h; benchmarking the most stable nonprecious HER catalyst in acidic media to date.
Original language | English |
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Journal | Journal of Catalysis |
Volume | 382 |
Pages (from-to) | 320-328 |
ISSN | 0021-9517 |
DOIs | |
Publication status | Published - 2020 |
Keywords
- 2D heterostructure
- Hydrogen evolution
- Stabilization function
- Vacancies
- Long-term stability