Publication Date

6-5-2020

Department

Ames Laboratory; Chemistry

Campus Units

Ames Laboratory, Chemistry

OSTI ID+

1638694

Report Number

IS-J 10249

DOI

1638694

Journal Title

Journal of Physical Chemistry C

Volume Number

124

Issue Number

25

First Page

13649

Last Page

13655

Abstract

Since the discovery of two-dimensional transition metal carbides, referred to as MXenes, research efforts have targeted their applications in energy storage, as lithium-ion batteries and supercapacitors. This interest is attributable to MXenes’ large volumetric capacitance, high rate handling capability, and stable cycling performance, which largely rely on the surface chemistry provided by the terminating groups, such as −OH, −O, and −F. However, the atomic-scale characterization of these surface terminations is challenging for diffraction methods. Solid-state (SS)NMR spectroscopy, especially 1H SSNMR, is a promising approach for scrutinizing the surface terminations and the intercalated water on an atomistic-scale; yet, only a few SSNMR studies of MXenes have been reported to date, offering conflicting results and limited understanding of −OH terminations. Here, we used 1H SSNMR experiments in concert with the DFT calculations of NMR parameters to identify multiple types of −OH groups residing on the external and internal surfaces in a commonly studied MXene, Ti3C2Tx. The study also identifies bulklike water trapped between the MXene flakes and interfacial water stranded on the surface. Lastly, two-dimensional 1H–1H correlation spectra elucidated the water–surface interactions and the mechanism of water deintercalation upon annealing.

DOE Contract Number(s)

AC02-07CH11358

Language

en

Department of Energy Subject Categories

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Publisher

Iowa State University Digital Repository, Ames IA (United States)

Available for download on Saturday, June 05, 2021

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