Dual-Site Substitution With Single Te Atoms in MoS₂ Boosting Hydrogen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Heteroatom substitution in molybdenum disulfide (MoS₂) enhances hydrogen evolution reaction (HER) activity.
• Simultaneously activating basal plane and edge sites of MoS₂ for HER remains a significant challenge.

Purpose of the Study:

• To develop a MoS₂-based catalyst with superior HER performance through dual-site heteroatom substitution.
• To investigate the synergistic effects of tellurium substitution on both Mo and S sites in MoS₂ for enhanced electrocatalysis.

Main Methods:

• Synthesized dual-site tellurium-substituted molybdenum disulfide (Te-MoS₂) via lattice substitution.
• Evaluated the HER performance of Te-MoS₂ in acidic electrolyte using electrochemical techniques.
• Conducted comprehensive analyses to understand the structural and electronic properties influencing catalytic activity.

Main Results:

• Te-MoS₂ exhibited superior large-current-density HER performance in acidic electrolyte.
• Achieved an overpotential of 364 mV for 1000 mA·cm^-2, surpassing commercial 20 wt% Pt/C (506 mV).
• Demonstrated stable HER performance for 200 hours without decay.

Conclusions:

• Simultaneous Te substitution at Mo and S sites effectively activates basal plane and edge sites in MoS₂.
• The Te-MoS₂ catalyst offers a promising alternative to precious metal catalysts for efficient HER.
• Optimized hydrogen adsorption energy at abundant S active sites contributes to the enhanced HER activity.