Hybrid carbon material discovery promises new application benefits
A metallic nanoribbon inside insulating nanotube can be considered as the thinnest insulated nanowire. Nanoribbons can be used directly inside of SWNTs to generate light and help produce LEDs. Semiconducting nanoribbons can also be used for transistor or solar cell applications.
“We came up with the idea to create a novel hybrid material, which combines two most fascinating carbon nanomaterials – single-walled carbon nanotubes and graphene,” said Doctor Albert Nasibulin from Aalto University.
SWNTs have a hollow space inside, which was used in this study as a 1-dimensional chemical reactor. A property of this space is that chemical reactions occur differently compared to the bulk 3D conditions. Large polyaromatic hydrocarbon molecules (coronene and perylene), which can be imagined as small pieces of graphene, were used as building blocks to produce long and narrow graphene nanoribbons inside the nanotubes.
The shape of encapsulated graphene nanoribbons can be modified by using different kinds of polyaromatic hydrocarbon molecules. Nanoribbons can be either metallic or semiconductor depending on their width and type. SWNTs can also be metallic, semiconducting (depending on their chirality) or insulating when chemically modified.
Metalli-metallic combination is a new kind of coaxial nanocables (widely used as transmitters of radio signals) in nanosize since the nanoribbons are not connected with nanotubes due to hydrogen atoms, which occupy all the edges of nanoribbons.
“Precise control of the width and angle of the graphene nanoribbons will help assembly materials based on graphene with strict control of the band gap. Such control is not possible for a macroscopic graphene, obtained by traditional technology,” explained Dr. Ilya Anoshkin.
The method of GNR@SWNT synthesis is simple, easily scalable and enables almost 100% of the tubes to be filled with nanoribbons.
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