title: Controlled Exfoliation of MoS2 Crystals into Trilayer Nanosheets.
abstract: The controlled exfoliation of transition metal dichalcogenides (TMDs) into pristine single- or few-layer nanosheets remains a significant barrier to fundamental studies and device applications of TMDs. Here we report a novel strategy for exfoliating crystalline MoS2 into suspensions of nanosheets with retention of the semiconducting 2H phase. The controlled reaction of MoS2 with substoichiometric amounts n-butyllithium results in intercalation of the edges of the crystals, which are then readily exfoliated in a 45 vol % ethanol-water solution. Surprisingly, the resulting colloidal suspension of nanosheets was found (by electron microscopy and atomic force microscopy) to consist mostly of trilayers. The efficiency of exfoliation of the pre-intercalated sample is increased by at least 1 order of magnitude relative to the starting MoS2 microcrystals, with a mass yield of the dispersed nanosheets of 11-15%.
authors.affiliation: State Key Laboratory of Chemical Engineering, Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University , Tianjin 300072, China.|Departments of Chemistry, Biochemistry and Molecular Biology, Physics, and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Fan
authors.affiliation: Departments of Chemistry, Biochemistry and Molecular Biology, Physics, and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Pengtao
authors.initials: P
authors.lastname: Xu
authors.affiliation: Departments of Chemistry, Biochemistry and Molecular Biology, Physics, and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Yuguang C
authors.initials: YC
authors.lastname: Li
authors.affiliation: Departments of Chemistry, Biochemistry and Molecular Biology, Physics, and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Dekai
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Departments of Chemistry, Biochemistry and Molecular Biology, Physics, and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Departments of Chemistry, Biochemistry and Molecular Biology, Physics, and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Minh An T
authors.initials: MA
authors.lastname: Nguyen
authors.affiliation: Departments of Chemistry, Biochemistry and Molecular Biology, Physics, and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Terrones
authors.affiliation: Departments of Chemistry, Biochemistry and Molecular Biology, Physics, and Center for 2-Dimensional and Layered Materials, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Mallouk