Synthesis and TEM structural characterization of C₆₀-flattened carbon nanotube nanopeapods

A fully flattened carbon nanotube (FNT), a graphene nanoribbon (GNR) analogue, provides a hollow space at edges for endohedral doping. Due to the unique shape of the hollow space of FNTs, novel types of low-dimensional arrangements of atoms and molecules can be obtained through endohedral doping into FNTs, which provides a new type of nanopeapods. FNT-based nanopeapods have been synthesized through endohedral doping of C₆₀, and their structural characterization with transmission electron microscopy (TEM) performed. The doping of C₆₀ into the inner hollow space of FNTs has been carried out via the gas-phase filling method, where open-ended FNTs are sealed in a glass ampoule and heated at 723–773 K for two days. TEM observations show that most of the encapsulated C₆₀ molecules align as single molecular chains along the edges of FNTs and that some of the C₆₀ forms two-dimensional close-packed structures inside FNTs.