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 language | English (US) |
|---|---|
| Pages (from-to) | 3550-3556 |
| Number of pages | 7 |
| Journal | Journal of Physical Chemistry C |
| Volume | 120 |
| Issue number | 6 |
| DOIs | |
| State | Published - Feb 18 2016 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
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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 journal › Article
TY - JOUR
T1 - Predicted Surface Composition and Thermodynamic Stability of MXenes in Solution
AU - Ashton, Michael
AU - Mathew, Kiran
AU - Hennig, Richard G.
AU - Sinnott, Susan B.
PY - 2016/2/18
Y1 - 2016/2/18
N2 - 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.
AB - 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.
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UR - http://www.scopus.com/inward/citedby.url?scp=84959010963&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.5b11887
DO - 10.1021/acs.jpcc.5b11887
M3 - Article
AN - SCOPUS:84959010963
VL - 120
SP - 3550
EP - 3556
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 6
ER -