Nanoconfined Solvothermal Synthesis of Defective 1T-MoS₂ Monolayers with High Electrocatalytic Performance.

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Controlled synthesis of 2D materials like molybdenum disulfide (MoS2) at scale is a significant challenge.
• Metallic phase 1T-MoS2 exhibits unique electronic properties valuable for catalysis.
• Existing methods often struggle with scalability and precise control over monolayer formation.

Purpose of the Study:

• To develop a scalable and controlled method for synthesizing 1T-MoS2 monolayers.
• To characterize the synthesized 1T-MoS2 nanosheets in terms of morphology, phase purity, and defect density.
• To evaluate the performance of the synthesized 1T-MoS2 as an electrocatalyst for the hydrogen evolution reaction (HER).

Main Methods:

• Nanoconfined solvothermal synthesis was employed for MoS2 monolayer production.
• Characterization techniques included assessment of monolayer ratio, 1T phase content, lateral size, and size distribution.
• In situ regulation of surface defect density was achieved by adjusting reaction conditions.
• Electrocatalytic activity for HER was tested, including overpotential and long-term stability measurements.

Main Results:

• Kilogram-scale synthesis of 1T-MoS2 monolayers with a 97% monolayer ratio and 89% 1T phase content was achieved.
• Nanosheets had controlled lateral sizes (100 nm to 1.0 µm) with narrow distribution and tunable surface defects.
• The synthesized 1T-MoS2 monolayers demonstrated excellent dispersibility and stability in various solvents.
• As an electrocatalyst for HER, 1T-MoS2 showed an overpotential of 315 mV at 1000 mA cm⁻² and superior stability over 100 hours, outperforming commercial Pt/C.

Conclusions:

• The nanoconfined solvothermal synthesis offers a scalable and controlled route to high-quality 1T-MoS2 monolayers.
• The synthesized 1T-MoS2 demonstrates exceptional electrocatalytic activity and stability for hydrogen evolution.
• This advancement paves the way for practical, large-scale applications of 2D materials in catalysis and beyond.