A facile and clean process for exfoliating MoS₂ nanosheets assisted by a surface active agent in aqueous solution

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Exfoliation of molybdenum disulfide (MoS2) into mono- and few-layer nanosheets is crucial for applications in electronics and sensors.
• Existing exfoliation methods often lack efficiency, environmental friendliness, or scalability.

Purpose of the Study:

• To develop a facile, efficient, and environmentally friendly liquid phase exfoliation method for MoS2.
• To investigate the role of surfactant concentration on exfoliation efficiency and nanosheet thickness.
• To demonstrate the potential of the exfoliated MoS2 nanosheets for solution-based device fabrication.

Main Methods:

• Liquid phase exfoliation of MoS2 using sodium dodecyl benzene sulfonate (SDBS) as a surfactant in an aqueous solution.
• Systematic variation of SDBS concentration to optimize exfoliation.
• Characterization of MoS2 nanosheets to determine thickness, defect levels, and dispersion stability.

Main Results:

• SDBS effectively exfoliates MoS2 layers due to the binding of its nonpolar benzene rings to the MoS2 surface.
• Exfoliation efficiency and nanosheet thickness are controllable by adjusting SDBS concentration.
• Defect-free mono- and few-layer MoS2 nanosheets were obtained.
• The exfoliated MoS2 nanosheets exhibited stable dispersion in water for extended periods (months).

Conclusions:

• The developed SDBS-assisted liquid phase exfoliation is a highly effective and scalable method for producing high-quality MoS2 nanosheets.
• The stable aqueous dispersion of MoS2 nanosheets opens avenues for low-cost, solution-based fabrication of electronic devices and sensors.
• This environmentally friendly approach advances the practical application of 2D materials like MoS2.