Surface chemistry studies have shown that designing precursor monomers on substrates (usually copper and other metal substrates) allows to control the polymerization reaction, thus to obtain graphene nanoribbons with controllable edges and widths (Cai et al. Nature, 2010, 466, 470- 473).

    Our previous studies have shown that carbon nanotubes can be used as nanoreactors in which controlled polymerization or decomposition-recombination resulted in confine graphene nanoribbons with specific widths and edge structures (Hans Kuzmany et al. Carbon 2021 , 171, 221-229; Yifan Zhang, et al. Nano Research 2022, 15, 1709−1714).

      Based on the above research, recently, we used terrylene (can be regarded as ultra-short 5-armchair graphene nanoribbons, abbreviated as 5AGNRs) as precursor molecule. By controlling the diameter of the carbon nanotubes it allows us to control the filling orientation of the terrylene molecules inside the carbon nanotubes, thus controlling the polymerization to be proceeded only in its length direction, resulting in 5AGNRs. More importantly, the conversion process of filled terrylene was studied by in-situ Raman spectroscopy, and the interference of terrylene adsorbed on the outside of carbon nanotubes on Raman spectroscopy analysis can be excluded. Therefore, the RBLM, C-H and other vibrational modes of the obtained 5AGNRs were finally confirmed.

    Paper information: Unravelling the Complete Raman Response of Graphene Nanoribbons Discerning the Signature of Edge Passivation. Small Methods, 2200110 (2022) Valeria Milotti, Claudia Berkmann, Jorge Laranjeira, Weili Cui, Kecheng Cao, Yifan Zhang, Ute Kaiser, Kazuhiro Yanagi, Manuel Melle-Franco, Lei Shi,* Thomas Pichler,* Paola Ayala*.

https://doi.org/10.1002/smtd.202200110