Marigold-flower-like MoS₂ nanosheet assemblies for enhanced alkaline hydrogen evolution.

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Developing efficient, cost-effective, and noble-metal-free electrocatalysts is crucial for sustainable hydrogen production through water splitting.
• Molybdenum disulfide (MoS2) is a promising material for electrocatalysis due to its unique properties.

Purpose of the Study:

• To synthesize hierarchical MoS2 nanosheets with a marigold flower-like morphology for enhanced hydrogen evolution reaction (HER) performance.
• To evaluate the electrochemical activity, stability, and potential of the synthesized MoS2 as a sustainable electrocatalyst.

Main Methods:

• Facile hydrothermal synthesis method for hierarchical MoS2 nanosheets.
• Characterization using X-ray Diffraction (XRD), Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), and Brunauer–Emmett–Teller (BET) analysis.
• Electrochemical evaluation including hydrogen evolution reaction (HER) measurements and chronoamperometric stability tests in 1.0 M KOH.

Main Results:

• Hierarchical MoS2 nanosheets with a marigold flower-like morphology and abundant exposed edge sites were successfully synthesized.
• The material exhibited excellent HER activity with a low overpotential of 180 mV at 10 mA cm-2 and a Tafel slope of 122.3 mV dec-1.
• Outstanding long-term stability over 10 hours was demonstrated, along with reduced charge-transfer resistance indicating efficient electron transport.

Conclusions:

• Hydrothermally synthesized hierarchical MoS2 nanosheets offer a promising, practical, and noble-metal-free electrocatalyst for sustainable hydrogen generation.
• The tailored morphology, high surface area, and favorable electronic structure contribute to the superior electrochemical performance.
• This study highlights the potential of MoS2-based materials in advancing clean energy technologies.