Carbon nanotubes (CNTs) have been a focus of nanomaterial research over the past two decades, due to their wide range of potential applications. In recent years, studies have shown a high degree of molecular control of CNTs in terms of number of layer, morphology and alignment, as well as great progress has been made toward preparing single-chirality single-walled carbon nanotubes (SWCNTs) through both direct controlled synthesis and post-synthesis separation approaches. However, challenges are still present in this field, regarding I) the development of a unique method which can produce selective SWCNTs with different chiral angles, II) assembly as macroscopic fiber by the direct spinning method with a high chirality control and III) the need to further clarify the growth mechanism of the nanotubes. The latter will be a great advance for the molecular and chirality control hence their properties.
Thus, my work as PhD Student in IMDEA Institute is targeted to work on selective chirality control of CNTs synthesized via FCCVD. Motivated by the challenge to develop a selective fabrication process of SWCNTs with controlled chirality, a new synthesis strategy is proposed, based on the use of pre-synthesized iron-platinum nanoparticles. My main concern is to control the structure and state of the catalyst which is considered to be responsible for the selective growth of chirality nanotubes. In this work, we review some recent progress made in the chirality-controlled synthesis of SWCNTs. Different techniques employed to determine the composition & structure, to isolate SWCNTs and for chirality characterization will be also highlighted and explained in detail.
In spite of not synthesizing nanotubes by this method, the results help to understand the possible growth mechanism of the nanotubes, the required state of the catalyst and to propose future experiments for chirality control. The last section of this work deals with these future experiments, for example, the use of Cobaltocene, Ruthenocene and FeO.Fe2O3 pre-synthesized nanoparticles as alternative catalysts.