Vertically aligned MoS₂ nanosheets on graphene for highly stable electrocatalytic hydrogen evolution reactions

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Efficient hydrogen evolution reaction (HER) electrocatalysts are crucial for clean energy technologies.
• Two-dimensional molybdenum disulfide (MoS2) shows promise but is limited by insufficient active edge sites.

Purpose of the Study:

• To develop an efficient HER electrocatalyst by vertically growing MoS2 nanosheets on graphene.
• To investigate the properties of the resulting van der Waals (vdW) heterostructure for improved charge transport and catalytic activity.

Main Methods:

• Vertically aligned MoS2 nanosheets were grown on graphene using chemical vapour deposition.
• Fabrication of a vdW heterostructure integrating MoS2 and graphene.
• Electrochemical characterization of the HER performance in an acid electrolyte.

Main Results:

• The graphene/MoS2 heterostructure exhibited a low turn-on potential of 0.14 V vs. RHE.
• The vertical vdW architecture demonstrated an 8x improvement in HER performance compared to layered MoS2.
• The catalyst showed high stability, operating continuously for over 50 hours and maintaining performance after 150 days.

Conclusions:

• The vertically aligned graphene/MoS2 heterostructure is a highly efficient electrocatalyst for HER.
• The unique vdW interface facilitates charge transport and enhances catalytic activity.
• This material presents a promising, stable, and cost-effective alternative for large-scale electrochemical applications.