Predicted Surface Composition and Thermodynamic Stability of MXenes in Solution

Michael Ashton, Kiran Mathew, Richard G. Hennig, Susan B. Sinnott

Research output: Contribution to journalArticle

68 Citations (Scopus)

Abstract

First-principles calculations are used to compare the binding energies of O, OH, and F on two-dimensional, metal carbide and nitride, or MXene, surfaces in order to predict the dependence of the thermodynamic stability of these compounds on their chemical composition. Solvation effects are implicitly included in the calculations to reproduce experimental conditions as closely as possible. The results indicate that all MXene surfaces are saturated with oxygen when exposed to H2O/HF solutions at low hydrogen chemical potential, μH, and that Sc-based MXenes can also be fluorinated in solutions of higherμH. After investigating the thermodynamic stability of all 54 MXene compounds Mn+1XnO2 (M = Sc, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta; X = C, N; n = 1, 2, 3), 38 are predicted to have formation energies below 200 meV/atom. Of these, six are predicted to have formation energies below 100 meV/atom, only one of which has been synthesized. Sc-based MXenes are found to be highly stable when their surfaces are terminated with F, which also results in the easiest exfoliation to produce freestanding single layers.

Original languageEnglish (US)
Pages (from-to)3550-3556
Number of pages7
JournalJournal of Physical Chemistry C
Volume120
Issue number6
DOIs
StatePublished - Feb 18 2016

Fingerprint

Surface structure
Thermodynamic stability
energy of formation
thermodynamics
Atoms
Hydrogen
Chemical potential
Solvation
Binding energy
Nitrides
carbides
nitrides
solvation
Carbides
atoms
chemical composition
binding energy
Metals
Oxygen
oxygen

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

Cite this

Ashton, Michael ; Mathew, Kiran ; Hennig, Richard G. ; Sinnott, Susan B. / Predicted Surface Composition and Thermodynamic Stability of MXenes in Solution. In: Journal of Physical Chemistry C. 2016 ; Vol. 120, No. 6. pp. 3550-3556.
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Predicted Surface Composition and Thermodynamic Stability of MXenes in Solution. / Ashton, Michael; Mathew, Kiran; Hennig, Richard G.; Sinnott, Susan B.

In: Journal of Physical Chemistry C, Vol. 120, No. 6, 18.02.2016, p. 3550-3556.

Research output: Contribution to journalArticle

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