Re Modulation of Metallic Ultrathin 2M-WS2 for Highly Efficient Hydrogen Evolution in Both Acidic and Alkaline Media

Metastable two-dimensional transition metal dichalcogenides (TMDs) are ideal electrocatalysts because of their excellent conductivities and high activities. However, metastable TMDs are generally unstable under electrochemical testing, especially after exfoliation with exposed abundant active sites. 2M-WS2, a typical TMD material with synergic metallic nature and exfoliative characteristics, offers great potential in catalyzing hydrogen evolution reaction (HER). Herein, we developed a unique Re modulation strategy to stabilize ultrathin 2M-WS2 nanosheets with less than four S-W-S stacking layers and enhanced intrinsic activity. Re-modulated 2M-WS2 (2M-RexW1-xS2) enables the robust chemical intercalation exfoliation to ultrathin nanosheets with additional active sites to promote the electrochemical activity. Meanwhile, the introduction of Re, an adjacent element to W for electronic modulation, could increase the electron density of states and improve structural stability. This work showcases a promising electronic modulation method to synergistically couple structural stability with catalytic activity for high-performance HER.

Automated summary

Metastable two-dimensional transition metal dichalcogenides (TMDs) are ideal electrocatalysts due to their excellent conductivities and high activities. This study developed a unique Re modulation strategy to stabilize ultrathin 2M-WS2 nanosheets and enhance their activity for hydrogen evolution reaction (HER), showcasing a promising electronic modulation method for high-performance HER.