Skip to Main content Skip to Navigation
Theses

Caractérisation des effets de surface, de désordre et d'empilement de feuillets dans le MXène Ti₃C₂Tₓ par microscopie électronique en transmission

Abstract : Surface chemistry, disorder and stacking effects play majors roles in the MXenes properties. Hence, characterizing those effects on the MXene electronic structure represents a fundamental concern for the study of these materials. Transmission electron microscopy allows to probe this electronic structure, from the micrometre to the nanometre scale, especially thanks to electron energy loss spectroscopy (EELS). The study focuses on the Ti₃C₂Tₓ MXene, T being surface groups.The first aim of the project was the study of the information that EELS may provide on the surface chemistry. By coupling this experimental spectroscopy technique with electronic structure simulations, it is shown that in the core losses, the carbon K edge provides the best marker, separating surface chemical modifications and volume disorder in the MXene sheets.Then the characterization of stacking sheets was approached, with the idea to provide, for the thinner samples, a quantitative thickness measurement, i.e. of the number of sheets. This second goal required the combination of the convergent beam electron diffraction, STEM-HAADF imaging and low-losses EELS spectroscopy experimental techniques, as well as density functional theory electronic structure simulations and diffraction pattern simulations using the Bethe theory of electron diffraction. In addition, the sensitivity of the volume plasmon to the average spacing between sheets was highlighted.These results were used to establish the role of an impurity on the electronic structure of the sheets and to characterize the MXene when used as an active phase support for the catalysis of the oxygen evolution reaction.
Document type :
Theses
Complete list of metadata

https://tel.archives-ouvertes.fr/tel-03185547
Contributor : Abes Star :  Contact
Submitted on : Tuesday, March 30, 2021 - 1:58:09 PM
Last modification on : Wednesday, March 31, 2021 - 3:23:52 AM

File

2021-BILYK-Thomas-These.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-03185547, version 1

Collections

Citation

Thomas Bilyk. Caractérisation des effets de surface, de désordre et d'empilement de feuillets dans le MXène Ti₃C₂Tₓ par microscopie électronique en transmission. Matériaux. Université de Poitiers, 2021. Français. ⟨NNT : 2021POIT2260⟩. ⟨tel-03185547⟩

Share

Metrics

Record views

65

Files downloads

33