Understanding the chiral selectivity of gold nanotubes

Based on first principles calculations, we show that both cohesive energy and string tension dictate the chiral selectivity of Au nanotubes (AuNTs). Moreover, they are linearly correlated with a new parameter that represents the bending degree of AuNTs. Upon the formation of AuNTs from planar Au belts, the energy of Au-dxydxy and Au-dx2−y2dx2−y2 bands is upshifted, which thus decreases the cohesive energy. Finally, it is found that AuNTs display more remarkable chiral selectivity than Ag nanotubes due to the higher slope of relative cohesive energy variations with respect to the bending degree.

► Au nanotubes (AuNTs) prefer the chirality of (n,[n/2])(n,[n/2]).
► A new parameter represents the bending degree of AuNTs.
► The bending of AuNTs upshift the energy states of dxydxy and dx2−y2dx2−y2 bands.