Support interactions dictated active edge sites over MoS₂-carbon composites for hydrogen evolution

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing efficient electrocatalysts for the hydrogen evolution reaction (HER) is crucial for clean energy technologies.
• Molybdenum disulfide (MoS2)-based materials are promising HER electrocatalysts, but their performance is limited by the availability and accessibility of active sites.

Purpose of the Study:

• To develop a rapid and efficient synthesis method for MoS2-based electrocatalysts with enhanced active edge sites.
• To comparatively investigate the effect of different carbon supports, reduced graphene oxide (rGO) and carbon nanotubes (CNTs), on the electrocatalytic activity of MoS2 for HER.

Main Methods:

• A microwave-assisted steam heating method was employed for the synthesis of lamellar MoS2 materials.
• MoS2 was combined with rGO and CNTs separately to assess support interactions and their impact on electrocatalytic activity.
• Electrocatalytic activity for HER was evaluated.

Main Results:

• The synthesis method successfully produced MoS2-based materials with favorable exposed active edge sites.
• CNTs demonstrated superior support interactions compared to rGO, suppressing in-plane growth and maximizing active edge sites.
• CNTs also helped maintain the intrinsic activity of MoS2, leading to synergistic enhancement of HER performance.

Conclusions:

• Support interactions play a critical role in optimizing the active edge sites of MoS2 for HER.
• CNTs are a more effective support material than rGO for enhancing MoS2 electrocatalytic activity for HER.
• The findings provide insights for the rational design of layered metal dichalcogenide electrocatalysts with improved active edges for HER.