PNNL

Abstract

We investigate the energetics of forming heteronanotubes, which are combinations of pure carbon nanotube (CNT) segments and boron-nitride nanotube (BNNT)segments. Our density functional theory calculations predict that the adverse impacts of heterojunctions on the nanotube stability can be minimized if the CNTand/or the BNNT building block segments are sufficiently large along the axial direction (corresponding to circular junctions). As such, carbon-boron-nitride heteronanotubes can be thermodynamically competitive in stability, as compared to pure CNTs and BNNTs of similar geometry, and this is in good agreement with previous experimental observations. In addition, we find that the highest occupied crystal orbital/lowest unoccupied crystal orbital (HOCO-LUCO) gap of carbon-boron-nitride heteronanotubes can be significantly tuned by modifying the CNT and BNNT combinations, the tube chirality, or the junction geometry (i.e., circular or linear).