Strain derived from bubbles at monolayer MoS2/hBN interfaces for enhanced hydrogen evolution reaction activity

Summary

Transition metal dichalcogenides (TMDs), notably monolayer MoS₂, are promising catalysts for the hydrogen evolution reaction (HER) due to their versatile surface and tunable band gap. Despite efforts to enhance catalytic activity, the impact of out-of-plane microstructure remains overlooked. In this study, we investigate the enhancement effect of bubbles on HER activity by fabricating bubbles with different curvatures at the interfaces between monolayer MoS₂ and hBN during a droplet-assisted transfer process. Bubbles induce the formation of strain on the MoS₂, enhancing the adsorption of protons and HER kinetics and leading to an exponential increase in HER activity (129.65 mA cm⁻² vs. 48.11 mA cm⁻² at −0.4 V vs. RHE). Theoretical calculations reveal that the synergistic interaction of S vacancies and tensile strain can generate more gap states near the Fermi level and enhance the adsorption of hydrogen. Our findings provide an updated understanding of the relationship between out-of-plane microstructure and activity.