Investigation on mechanical and electronic properties of graphene-doped boron nitride nanotubes

Abstract

In this work, mechanical properties and failure process under axial tension loading of hybrid boron nitride nanotubes (BNNTs) embedded with hexagonal or triangular graphene sheets were investigated using density functional theory method. Compared with the pristine BNNT, the intrinsic strength of the hybrid BNNTs increased while the stiffness decreased caused by the disturbance of embedded graphene sheets. C–B and C–N bonds are formed in the carbon/boron nitride interface structure that determines the fracture mechanism. Compared with the C–N bond, the C–B interface bond would lead to more damage for the symmetry of the tubes, which makes C–B bonds act as the main initial break site during the tensile test. In the hybrid BNNTs with a C–N interface, the B–N bonds near the C–N interface break initially. The band gap of hybrid BNNTs decreased due to the doping of the carbon domains. Applying strain on the nanotubes can also reduce the band gap. The special interface plays an important role on manipulating the mechanical properties and band structure for the hybrid BNNTs.