Liquid-Phase Exfoliation of MoS2 Nanosheets: The Critical Role of Trace Water

Gupta, Amit and Arunachalam, Vaishali and Vasudevan, Sukumaran (2016) Liquid-Phase Exfoliation of MoS2 Nanosheets: The Critical Role of Trace Water. In: Journal of Physical Chemistry Letters, 7 (23). pp. 4884-4890.

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Abstract

Sonication-assisted liquid-phase exfoliation of layered materials in suitable organic solvents offers a simple scalable route for the production of 2D nanomaterials. N-methyl-2-pyrrolidone (NMP) is one of the most efficient solvents for liquid-phase exfoliation of a variety of layered solids, including MoS2. We show here that trace water present in NMP is crucial for the stability of MoS2 nanosheets in NMP dispersions. In the absence of water, the sheets are fragmented and chemically unstable. Using solution NMR techniques, 2D nuclear Overhauser effect and spin-lattice relaxation measurements, supported by classical molecular dynamics simulations, we are able to establish the role of water molecules in stabilizing the dispersion. We show that water molecules are localized at the Mo-terminated edges of the MoS2 sheets, thereby inhibiting chemical erosion of the sheets, and they also exhibit enhanced interactions with the solvent NMP molecules, leading to the stability of the dispersion.

Item Type:	Journal Article
Publication:	Journal of Physical Chemistry Letters
Publisher:	AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
Additional Information:	Copy right for this article belongs to the AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	04 Jan 2017 05:28
Last Modified:	04 Jan 2017 05:28
URI:	http://eprints.iisc.ac.in/id/eprint/55854

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