Shape controllable MoS₂ nanocrystals prepared by the single precursor route for electrocatalytic hydrogen evolution

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Molybdenum disulfide (MoS₂) is a promising, earth-abundant electrocatalyst for hydrogen production through water electrolysis.
• Bulk MoS₂ exhibits limited electrocatalytic activity due to poor electrical conductivity and a scarcity of active edge sites.

Purpose of the Study:

• To develop a facile synthesis strategy for nanoscale MoS₂ with diverse morphologies.
• To investigate the structure-activity relationship of MoS₂ nanomaterials in electrocatalytic hydrogen evolution.

Main Methods:

• A single-precursor strategy was employed for the controllable synthesis of MoS₂ nanomaterials.
• Morphologies including quantum dots, nanorods, nanoribbons, and nanosheets were prepared.
• Electrocatalytic performance was evaluated using water electrolysis tests.

Main Results:

• The morphology of MoS₂ was found to be controllable by adjusting kinetic and thermodynamic factors like reaction time and temperature.
• MoS₂ quantum dots exhibited superior electrocatalytic performance.
• MoS₂ quantum dots achieved a low overpotential of 255 mV and a Tafel slope of 66 mV dec^-1.

Conclusions:

• Nanoscale MoS₂ with engineered morphologies, particularly quantum dots, significantly enhances electrocatalytic activity for hydrogen production.
• The improved performance is attributed to abundant exposed active edges and excellent intrinsic conductivity of MoS₂ quantum dots.
• This study highlights the potential of tailored MoS₂ nanostructures as efficient electrocatalysts for sustainable hydrogen generation.