By a combination of the first-principles calculations and climbing image nudged elastic band method (ciNEB) we investigate structure stabilities and hydrogen evolution reaction (HER) performance of monolayer 2H-CrS2. The results suggest the free energy for the Volmer reaction in the monolayer 2H-CrS2 with S vacancy is 0.07 eV, comparable with Pt-based catalyst, and HER on the surface of the monolayer is prone to the Volmer-Heyrovsky mechanism with no energy barrier. We propose that high HER performance stems from the reduction of the energy level of d-band center. Additionally, the S vacancy leads to defect states in the middle of electronic bandgap and the reduction of potential barrier between the S atom layer and the vacuum, which is conducive to improve HER performance.
@article{arxiv.2001.06161,
title = {Prediction for structure stability and ultrahigh hydrogen evolution performance of monolayer 2H-CrS2},
author = {Feng Sun and Aijun Hong and Wenda Zhou and Cailei Yuan and Wei Zhang},
journal= {arXiv preprint arXiv:2001.06161},
year = {2020}
}