Theoretical Study of the Mechanical Behavior of Individual TiS₂ and MoS₂ Nanotubes

Abstract

Similar to carbon, several transition-metal chalcogenides are able to form tubular structures. Here, we present results from systematic theoretical investigations of structural and mechanical properties of MoS2 and TiS2 nanotubes in comparison to each other, to carbon nanotubes, and to corresponding experimental results. We have obtained the nanotube’s Young’s moduli (Y), Poisson ratios (ν), and shear moduli (G) as functions of diameter and chirality, using a density-functional-based tight-binding method. Additionally, we have simulated tensile tests by Born–Oppenheimer molecular dynamics simulations. The influence of structural defects on the investigated mechanical properties has been studied as well. As a result of the simulated stretching experiments, we found that TiS2 nanotubes can be stretched only half as much as MoS2 nanotubes.

Single- to Triple-Wall WS2 Nanotubes Obtained by High-Power Plasma Ablation of WS2 Multiwall Nanotubes

“…This makes the WS 2 layers pretty rigid, with interlayer spacing of 6.23 Å; it is no wonder that the elastic energy for WS 2 (MoS 2 ) nanotube formation is appreciably larger than that of graphitic carbon. If one takes the elastic energy threshold for folding to be 0.05 eV/atom, the calculated diameter of a single-wall carbon nanotube is between one and 1.2 nm [25], and that of a single-wall MoS 2 should be 6.2 nm [9,26]. Therefore, the diameters of the daughter WS 2 nanotubes observed in the current series of experiments reconcile very well with the previous calculations.…”

An ab initio study of the size-dependent mechanical behavior of single-walled AlN nanotubes

“…Young's modulus has been calculated from the second derivative of the total energy E with respect to the strain ε at the equilibrium volume V 0 [31,32]. …”

Mechanical Properties, Electronic Structures, and Potential Applications in Lithium Ion Batteries: A First-Principles Study toward SnSe2 Nanotubes

“…For example, as a similar structural orientation to the SnSe 2 nanotube, a recent study reported the Young's modulus of the TiS 2 (1T structure, where the metal atoms are coordinated octahedrally by the sulfur atom as in the case of SnSe 2 ) nanotube reaches 140 GPa· nm. 62 Our area-based Young's moduli of SnSe 2 ANT and ZNT are calculated to be 59 and 57 GPa·nm, respectively. The significant lower values indicate that the SnSe 2 nanotube is softer than the TiS 2 nanotube.…”