Large-scale production of defect-free MoS2 nanosheets via pyrene-assisted liquid exfoliation

Two dimensional (2D) layered MoS 2 nanosheets are gaining increasing attention due to their attractive properties associated with myriads potential applications. However, large-scale production of high-quality MoS 2 nanosheets in a simple manner remains a big challenge. Herein, we present a facile approach for scalable production of defect-free MoS 2 nanosheets by direct ultrasonication exfoliation of bulk MoS 2 crystals in ethanol in the presence of pyrene. Our findings indicate that the pyrene can not only serve as an exfoliating agent to significantly accelerate the exfoliation process but also endow the resulted MoS 2 nanosheets with excellent solution dispersibility and stability. The obtained MoS 2 nanosheets are highly crystalline and exhibit superior electrical properties as compared with the bulk MoS 2 . In addition, the MoS 2 nanosheets can also be employed as nanofillers to enhance the mechanical properties of polymers. Moreover, this method can also be extended to exfoliation of other 2D layered transition metal dichalcogenide as demonstrated by the exfoliation of bulk WS 2 crystals in this study. This work thus brings more opportunities for the investigation and applications of 2D layered inorganic nanosheets.