Polyiodide structures in thin single-walled carbon nanotubes: A large-scale density-functional study
| Autor: | Anthony Impellizzeri, D. V. Rybkovskiy, Elena D. Obraztsova, Christopher P. Ewels |
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| Rok vydání: | 2019 |
| Předmět: |
Nanotube
Materials science Charge (physics) Fermi energy 02 engineering and technology General Chemistry Carbon nanotube 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences law.invention Polyiodide chemistry.chemical_compound Electron transfer chemistry Chemical physics law Metastability General Materials Science 0210 nano-technology Fermi Gamma-ray Space Telescope |
| Zdroj: | Carbon. 142:123-130 |
| ISSN: | 0008-6223 |
| Popis: | Using automatic structure generation algorithms and large-scale density functional computations we study polyiodide structures encapsulated within a 1 nm diameter single-walled carbon nanotube. The most energetically preferable confined iodine structures are the I3−, I5− and I82− molecular anions and periodic single, double and triple chain systems. The formation energy drops with increasing number of iodine atoms, reaching a minimum for a single iodine chain. Double and triple chains are metastable but have higher formation energies due to spatial confinement within the thin carbon nanotube. The calculated electron transfer from the nanotube to the molecular structures is close to the integer charge values of the molecular anions. The corresponding Fermi energy shift depends on the iodine concentration. For the single, double and triple chains the calculated Fermi shift is ∼0.13, ∼0.23 and ∼0.19 eV below the top of the nanotube valence band, respectively. The computational approaches presented here require minimal a priori knowledge of the system under study, yet are able to predict stable iodine structures observed in experiment. |
| Databáze: | OpenAIRE |
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