AVS 64th International Symposium & Exhibition
    2D Materials Focus Topic Wednesday Sessions
       Session 2D-WeA

Paper 2D-WeA8
Lithium-Free Covalent Chemical Functionalization of Two-Dimensional Molybdenum Disulfide

Wednesday, November 1, 2017, 4:40 pm, Room 15

Session: Properties and Characterization of 2D Materials
Presenter: Qing Hua Wang, Arizona State University
Authors: X.S. Chu, Arizona State University
A. Yousaf, Arizona State University
D.O. Li, Arizona State University
A.A. Tang, Arizona State University
A. Debnath, Arizona State University
D. Ma, Arizona State University
A.A. Green, Arizona State University
E.J.G. Santos, Queen's University Belfast, UK
Q.H. Wang, Arizona State University
Correspondent: Click to Email
Two-dimensional transition metal dichalcogenides like molybdenum disulfide (MoS2) are generating significant excitement due to their unique electronic, chemical, and optical properties. Chemical functionalization is crucial for tuning their properties for use in many applications. Previous methods to covalently functionalize the basal planes of TMDCs require using harsh lithium compounds for intercalation, exfoliation, and phase change from semiconducting to metallic. Here, we demonstrate the direct covalent functionalization of unmodified semiconducting MoS2 using aryl diazonium salts without lithium treatments. Our approach preserves the structure and semiconducting nature of MoS2, results in covalent C-S bonds, and is applicable to MoS2 derived from mechanical exfoliation, chemical vapour deposition, and liquid phase dispersion. We use density functional theory including van der Waals interactions to determine the reaction mechanism, and support it by scanning probe microscopies. The flexibility of this covalent chemistry is exploited to tether active proteins to MoS2, suggesting future biological applications.