Bulusheva, L. G., Lobiak, E., Fedoseeva, Y., Mevellec, J. .-Y., Makarova, A. A., Flahaut, E. & Okotrub, A. (2020) Effect of ultrasound pretreatment on bromination of double-walled carbon nanotubes. Synth. Met. 259 116233.
Added by: Richard Baschera (2020-02-24 14:32:42) Last edited by: Richard Baschera (2020-02-24 16:54:40) |
Type de référence: Article DOI: 10.1016/j.synthmet.2019.116233 Numéro d'identification (ISBN etc.): 0379-6779 Clé BibTeX: Bulusheva2020 Voir tous les détails bibliographiques |
Catégories: IMN, INTERNATIONAL Mots-clés: Br-2 adsorption, bromination, carbon nanotubes, Density functional theory calculations, electronic-properties, functionalization, graphene, graphitic materials, purification, supercapacitor performance, surfaces, transport, X-ray photoelectron spectroscopy, XPS Créateurs: Bulusheva, Fedoseeva, Flahaut, Lobiak, Makarova, Mevellec, Okotrub Collection: Synth. Met. |
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Résumé |
Bromination of double-walled carbon nanotubes (DWCNTs) was carried out using a saturated vapor of Br-2 at room temperature with or without a pretreatment in bromine water. X-ray photoelectron spectroscopy revealed that ultrasound pretreatment modified the chemical state of bromine in the product. The binding energies of the Br 3d electrons in the pre-sonicated DWCNT sample were between those characteristic of the covalent C-Br bonds and the negatively charged Br-2 molecules, observed when the pretreatment was not performed. Raman spectroscopy, however, clearly evidenced Br-Br vibrations in both brominated samples. Calculations of CNT-Br-2 models within density functional theory were used to propose that the electronic state of a Br-2 molecule depends on the adsorption site. The bromine molecules prefer to be located near edge hydroxyl groups, which acept the electron density from Br-2. This increases the binding energy of Br 3d levels as compared to that for Br-2 molecules in other adsorption sites.
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