Inorganic fullerene-like structures

Besides nanotubes, layered materials are able to build up other hollow nanostructures, such as fullerenes, nanoonions, or nanoseashells. For carbon, many of these systems have been synthesized experimentally. It is possible to construct theoretically and synthesize experimentally corresponding inorganic nanostructures. Prominent examples are inorganic multi-walled fullerenes built up from WS2, M0S2 or V2O5. These inorganic fullerenes are by now even synthesized in large quantities for applications as technical lubricants and have been studied experimentally and theoretically. 

Two examples for nanooctahedra and nanoseashells are shown in Fig. 6. Whereas the nanooctahedra (right-hand side of Fig. 6) are closed structures, nanoseashells must have grown asymmetrically. As a result, the structure is not closed, but rolled up in a three-dimensional way resembling the spiral form of some seashells or cephalopods. The closed-shell nanooctahedra appear as well in distorted shapes that might even have more than eight facets. 

In this chapter we have reviewed the latest contributions within the field of modelling inorganic nanotubes and inorganic fullerene-like structures. We have seen that many inorganic layered materials are able to form hollow nanostructures similar to systems formed by graphene and other forms of carbon. Most of the materials studied theoretically have been experimentally synthesized as well. Some of them are even produced in large amounts for industrial applications. 

Using helical boundary conditions within an objective molecular-dynamics scheme it is possible to describe chiral nanotubes with reasonable computational effort. With this approach it could be shown that chiral M0S2 and T1S2 nanotube families are intrinsically twisted. However, this effect is only small. Additionally, it was shown that also the mechanical and electronic properties depend on the chirality, if the tubes have diameters smaller than 7 nm. On the other hand, tubes with larger diameters are chirality-independent. 

A solid encapsulation, such as transition metal nanowires within boron nitride nanotubes, is a different system. Computationally, it is difficult to study, since the lattice constants of tube and wire have to be adjusted in an approach using periodic-boundary conditions. The energetics depend on the relation of the diameters of nanotube and eneapsulated nanowire. 

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This chapter is structured as follows we will discuss the structure of carbon and inorganic nanotubes in general in Section 2, followed by synopses of studies of structural properties of elemental inorganic nanotubes and intrinsically twisted inorgnic nanotubes in Sections 3 and 4, respectively. Section 5 discusses the encapsulation of materials in and the filling process of inorganic nanotubes, whereas Section 6 features inorganic fullerene-like structures. We conclude in Section 7. 

Inorganic Nanoclusters with Fullerene-Like Structure and Nanotubes... 

II. CLASSIFICATION OF DIFFERENT INORGANIC COMPOUNDS FORMING FULLERENE-LIKE STRUCTURES AND NANOTUBES... 

Tenne, R., Inorganic Nanoclusters with Fullerene-Like Structure and Nanotubes Thomas, Douglas, see Miranda, Katrina M. 

Inorganic Nanoparticles with Fullerene-like Structure and Nanotubes Some Electrochemical and Photoelectrochemical Aspects... 

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