Structure of inorganic nanocrystals confined within carbon nanotubes

[Display omitted] •CNTs can be filled with inorganic crystals with diverse structural characteristics.•Confinement within CNTs lead to the formation of unprecedented nanostructures.•The structure of the guest is ruled by the inner dimensions of the hosting CNTs.•CNTs provide interesting characteristics to the new synthesized hybrids. There are many examples in which the cavities of carbon nanotubes have been filled with a variety of compounds. Unprecedented structures compared to those of the same material in the bulk are observed, such as low dimensional crystals. Such encapsulated materials can have unusual properties that differ from those of the bulk material. The scope of this review is to give a brief approach to the different nanostructures formed after encapsulation of inorganic compounds within the inner cavities of carbon nanotubes. The confined materials can take the form of one-dimensional nanowires, nanoclusters or even inorganic nanotubes. This review is part of the special issue of the journal dedicated to Prof. Malcolm L.H. Green, and special emphasis is thus given to the work performed by the group of Prof. Green.