Bromine polycondensation in pristine and fluorinated graphitic carbons
| Autor: | Alexander V. Okotrub, O. V. Sedelnikova, Galina N. Chekhova, D. V. Pinakov, Lyubov G. Bulusheva, Christopher P. Ewels, Emmanuel Flahaut |
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| Přispěvatelé: | Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Novosibirsk State University (RUSSIA), Siberian Branch of the Russian Academy of Sciences - SB RAS (RUSSIA), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Nantes (FRANCE), Institut des Matériaux Jean Rouxel - IMN (Nantes, France), Nikolaev Institute of Inorganic Chemistry [Novosibirsk] (NIC), Siberian Branch of the Russian Academy of Sciences (SB RAS), Novosibirsk State University (NSU), Institut des Matériaux Jean Rouxel (IMN), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN), Centre interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Nova Southeastern University (NSU), Institut National Polytechnique de Toulouse - INPT (FRANCE) |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Matériaux Intercalation (chemistry) chemistry.chemical_element Fluorinated graphitic carbon 02 engineering and technology 010402 general chemistry 01 natural sciences law.invention [SPI.MAT]Engineering Sciences [physics]/Materials symbols.namesake law Molecule General Materials Science Compounds of carbon chemistry.chemical_classification Polycondensation Bromine Graphene 021001 nanoscience & nanotechnology 0104 chemical sciences Crystallography chemistry symbols Density functional theory 0210 nano-technology Raman spectroscopy Carbon |
| Zdroj: | Nanoscale Nanoscale, Royal Society of Chemistry, 2019, 11 (32), pp.15298-15306. ⟨10.1039/c9nr01922g⟩ |
| ISSN: | 2040-3364 2040-3372 |
| DOI: | 10.1039/c9nr01922g⟩ |
| Popis: | International audience; Despite decades of study the precise behavior of bromine in graphitic carbons remains unclear. In this report, using Raman spectroscopy, we reveal two types of bromine structure in graphitic carbon materials. Between fluorinated graphene layers with a composition close to C2F, Br2 molecules are intercalated in a form similar to liquid bromine. Bromination of pristine and low-fluorinated graphitic carbons behaves very differently with distinct Br-related Raman spectra. With the guidance of density functional theory (DFT) calculations, all Raman features are assigned to normal vibration modes of specific bromine species over graphene and fluorinated graphene. When intercalated between extended non-fluorinated sp2-hybridized carbon regions, physisorbed Br2 molecules move freely across the non-functionalized region toward the CF border. Multiple Br2 molecules then combine spontaneously into Br3-based chains, whose coupling activates otherwise Raman inactive modes. Significant charge transfer to bromine species occurs in this case. DFT calculated frequencies match precisely the experimental Br-related Raman bands observed in the intercalation carbon compounds. The fluorine-catalyzed bromine chain-formation process shown here is general and should also operate with edges and other defect species. |
| Databáze: | OpenAIRE |
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