Reasonable BN nanotubes composed of B–B and N–N bonds: A theoretical prediction

What kinds of the nanotubes rolled from the rectangular di-BN are indeed reasonable? In order to clarify this question, two types of mathematically and physically rigorous boron nitride nanotubes (di-BNNTs) along the (n,0) and (0,n) chiral vectors, composed of diboron B−−B and azo N−−N bonds, are investigated with the aid of density functional theory (DFT) simulations. Firstly, there is no chiral nanotube with (n,m) at all by considering its 1D periodicity. Secondly, the phonon dispersion relations clearly support the lattice dynamic stabilities of the thinnest zigzag (6,0) and armchair (0,4) di-BNNTs with the radii of 2.385 Å and 2.911 Å, respectively. The ab-initio molecular dynamics (AIMD) simulations further confirm their thermodynamic stabilities at least at 1000 K. Furthermore, the energetic, mechanical, and electronic features of these two kinds of di-BNNTs are systematically studied. According to our calculations, di-BNNTs possess excellent mechanical strengths and adjustable band gaps, which endow them the promising application potential in solar conversion field.