An ab initio investigation into the elastic, structural and electronic properties of MoS2 nanotubes

Environmentally hazardous gas sensing ability of MoS2-nanotubes: an insight from the electronic structure and transport properties

“…The optimized lattice parameter for the (6,6) MoS 2 -NT was found to be 3.23Å, which is much better than that found in previous theoretical studies. 27 NT@CO 2 system, the adsorption energy at the S-site is À0.12 eV and for MoS 2 -NT@NH 3 and MoS 2 -NT@H 2 O, where adsorption is on the M-site, the adsorption energy values are À0.94 eV and À1.74 eV, respectively. The negative adsorption energies reveal that the adsorption is purely exothermic and therefore energetically favourable in all cases.…”

“…24 Among these two forms, the armchair (n,n) MoS 2 -NT shows an indirect band gap whereas the zigzag form shows a direct band gap. For the (n,n) MoS 2 -NT, the band gap increases with the increase in the magnitude of n. 27 MoS 2 -NT systems can sense NH 3 and NO 2 gases. 28 There are several reports on the variation of gas sensing properties of MoS 2 -monolayer along with some other TMD materials, but the atomistic description of gas sensing ability of MoS 2 -NTs is scarce.…”

Size-dependent trends in the hydrogen evolution activity and electronic structure of MoS2 nanotubes

“…Specically, in the clean nanotube DOS, it appears that the gap between the edge of the lled S pstates and the unlled Mo d-states reduces in smaller nanotubes. It has previously been found that the overall band gap of MoS 2 nanotubes reduces with their diameter, 42,45 but here the S p-and Mo-d states are studied specically, because H binding involves an electron transfer between these two states. We propose that the lowering of DG H ads values on smaller nanotubes is a direct result of the reduction of this energy gap.…”

Torsional moduli of transition metal dichalcogenide nanotubes from first principles

“…Among the different groups, the transition metal dichalcogenide (TMD) group -materials of the form MX 2 , where M and X represent a transition metal and chalcogen, respectively -is currently the most diverse, particularly given that they contain the largest number of distinct nanotubes synthesized to date 2-4 . TMD nanotubes have a number of interesting properties including high tensile strength 7-10 , mechanically tunable electronic properties [11][12][13][14][15][16][17] , and low cytotoxicity 18 . These properties make TMD nanotubes suited to a number of applications, including reinforcement of composites [19][20][21][22][23][24] , nanoelectromechanical (NEMS) devices 17,25,26 , and medicine 27 , where knowledge of their mechanical properties is important from the perspective of both design and performance.…”

“…In view of the above, there have been a number of efforts to characterize the elastic properties of TMD nanotubes, both experimentally 9,28-30 and theoretically 11,13,16,[31][32][33][34][35][36][37][38] . However, these studies are limited to only a few TMDs, and that too only for the case of axial tension/compression.…”