Chirality-Driven Electronic, Mechanical, and Hydrogen Adsorption Properties of Dodecanophene Nanotubes

We report a detailed theoretical investigation into the electronic, mechanical, and hydrogen adsorption behaviors of zigzag dodecanophene nanotubes (Dode-NTs) with chiralities (n,0) and (0,n). Using density functional theory (DFT) and classical reactive molecular dynamics (MD) simulations, we demonstrate that chirality and curvature strongly modulate the physical behavior of these nanotubes. The Dode-NTs (n,0) maintain a robust metallic character even under uniaxial strain, whereas Dode-NTs (0,n) with odd chiral indices exhibit a tunable semiconducting behavior, with frontier orbitals spatially separated along transverse and longitudinal directions. Mechanically, Dode-NTs (n,0) exhibit higher stiffness and tensile strength, confirmed by both DFT and MD, while Dode-NTs (0,n) show a more ductile response with distributed strain accommodation. These features highlight a pronounced mechanical anisotropy. The hydrogen adsorption studies reveal that the Dode-NTs (n,0), particularly at a specific adsorption site and at larger diameters, exhibit adsorption free energy values near the catalytic optimum for the hydrogen evolution reaction (HER). In contrast, Dode-NTs (0,n) present lower reactivity and weaker site selectivity. MD results confirm a more efficient surface functionalization for the Dode-NTs (n,0) configuration under elevated temperatures. These findings highlight that Dode-NTs, especially those with (n,0) chirality, are highly tunable nanostructures with potential applications in catalysis, hydrogen storage, nanoelectronics, and nanomechanical systems.