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

A facile, efficient and environmentally friendly process to exfoliate MoS₂ is essentially critical to apply the obtained mono- and few-layer nanosheets in various electronic devices and sensors. Here we report a liquid phase exfoliation method for exfoliation of MoS₂, which employs a surfactant of sodium dodecyl benzene sulfonate (SDBS) in water. The nonpolar benzene rings in SDBS can firmly bind to the MoS₂ layer, facilitating the effective exfoliation of nanosheets in aqueous solution. It is found that the exfoliation efficiency and thickness of MoS₂ nanosheets are related to the concentration of SDBS, and the mechanism was investigated. Defect free mono- and few-layer MoS₂ nanosheets are obtained by controlling the amount of SDBS in solution, which exhibit stable dispersion in water over months, and it renders them as having great potential for solution-based device fabrication.