Coronene Encapsulation in Single-Walled Carbon Nanotubes: Stacked Columns, Peapods, and Nanoribbons

• Published in: Chemphyschem 2014-06, Vol.15 (8), p.1660-1665
• Main Authors: Anoshkin, Ilya V., Talyzin, Alexandr V., Nasibulin , Albert G., Krasheninnikov, Arkady V., Jiang, Hua, Nieminen, Risto M., Kauppinen, Esko I.
• Format: Article
• Language: English
• Subjects: coronene; encapsulation; graphene; nanoribbons; nanotubes
• ISSN: 1439-4235; 1439-7641; 1439-7641
• DOI: 10.1002/cphc.201301200

Encapsulation of coronene inside single‐walled carbon nanotubes (SWNTs) was studied under various conditions. Under high vacuum, two main types of molecular encapsulation were observed by using transmission electron microscopy: coronene dimers and molecular stacking columns perpendicular or tilted (45–60°) with regard to the axis of the SWNTs. A relatively small number of short nanoribbons or polymerized coronene molecular chains were observed. However, experiments performed under an argon atmosphere (0.17 MPa) revealed reactions between the coronene molecules and the formation of hydrogen‐terminated graphene nanoribbons. It was also observed that the morphology of the encapsulated products depend on the diameter of the SWNTs. The experimental results are explained by using density functional theory calculations through the energies of the coronene molecules inside the SWNTs, which depend on the orientation of the molecules and the diameter of the tubes. Argon or vacuum? Encapsulation of coronene into single‐walled carbon nanotubes (SWNTs) under an atmosphere of argon results in the preferential formation of graphene nanoribbons. Vacuum conditions favor encapsulation of monomer (coronene) and dimer (dicoronylene) molecules in a variety of geometries, including stacking columns and peapods. The morphology of the encapsulated products depends on the diameter of the SWNTs.