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pH-Dependent Distribution of Functional Groups on Titanium-Based MXenes

[Image: see text] MXenes are a new rapidly developing class of two-dimensional materials with suitable properties for a broad range of applications. It has been shown that during synthesis of these materials the surfaces are usually functionalized by O, OH, and F and further suggested that controlli...

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Autores principales: Ibragimova, Rina, Puska, Martti J., Komsa, Hannu-Pekka
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2019
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6748675/
https://www.ncbi.nlm.nih.gov/pubmed/31393102
http://dx.doi.org/10.1021/acsnano.9b03511
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author Ibragimova, Rina
Puska, Martti J.
Komsa, Hannu-Pekka
author_facet Ibragimova, Rina
Puska, Martti J.
Komsa, Hannu-Pekka
author_sort Ibragimova, Rina
collection PubMed
description [Image: see text] MXenes are a new rapidly developing class of two-dimensional materials with suitable properties for a broad range of applications. It has been shown that during synthesis of these materials the surfaces are usually functionalized by O, OH, and F and further suggested that controlling the surface allows controlling the material properties. However, a proper understanding of the surface structure is still missing, with a significant discrepancy between computational and experimental studies. Experiments consistently show formation of surfaces with mixed terminations, whereas computational studies point toward pure terminated surfaces. Here, we explain the formation of mixed functionalization on the surface of titanium-based two-dimensional carbides, Ti(2)C and Ti(3)C(2), using a multiscale modeling scheme. Our scheme is based on calculating Gibbs free energy of formation by a combination of electronic structure calculations with cluster expansion and Monte Carlo simulations. Our calculations show formation of mixtures of O, OH, and F on the surface with the composition depending on pH, temperature, and the work function. On the other hand, our results also suggest a limited stable range of compositions, which challenges the paradigm of a high tunability of MXene properties.
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spelling pubmed-67486752019-09-18 pH-Dependent Distribution of Functional Groups on Titanium-Based MXenes Ibragimova, Rina Puska, Martti J. Komsa, Hannu-Pekka ACS Nano [Image: see text] MXenes are a new rapidly developing class of two-dimensional materials with suitable properties for a broad range of applications. It has been shown that during synthesis of these materials the surfaces are usually functionalized by O, OH, and F and further suggested that controlling the surface allows controlling the material properties. However, a proper understanding of the surface structure is still missing, with a significant discrepancy between computational and experimental studies. Experiments consistently show formation of surfaces with mixed terminations, whereas computational studies point toward pure terminated surfaces. Here, we explain the formation of mixed functionalization on the surface of titanium-based two-dimensional carbides, Ti(2)C and Ti(3)C(2), using a multiscale modeling scheme. Our scheme is based on calculating Gibbs free energy of formation by a combination of electronic structure calculations with cluster expansion and Monte Carlo simulations. Our calculations show formation of mixtures of O, OH, and F on the surface with the composition depending on pH, temperature, and the work function. On the other hand, our results also suggest a limited stable range of compositions, which challenges the paradigm of a high tunability of MXene properties. American Chemical Society 2019-08-08 2019-08-27 /pmc/articles/PMC6748675/ /pubmed/31393102 http://dx.doi.org/10.1021/acsnano.9b03511 Text en Copyright © 2019 American Chemical Society This is an open access article published under a Creative Commons Attribution (CC-BY) License (http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html) , which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.
spellingShingle Ibragimova, Rina
Puska, Martti J.
Komsa, Hannu-Pekka
pH-Dependent Distribution of Functional Groups on Titanium-Based MXenes
title pH-Dependent Distribution of Functional Groups on Titanium-Based MXenes
title_full pH-Dependent Distribution of Functional Groups on Titanium-Based MXenes
title_fullStr pH-Dependent Distribution of Functional Groups on Titanium-Based MXenes
title_full_unstemmed pH-Dependent Distribution of Functional Groups on Titanium-Based MXenes
title_short pH-Dependent Distribution of Functional Groups on Titanium-Based MXenes
title_sort ph-dependent distribution of functional groups on titanium-based mxenes
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6748675/
https://www.ncbi.nlm.nih.gov/pubmed/31393102
http://dx.doi.org/10.1021/acsnano.9b03511
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