Coaxial heterostructure formation of highly crystalline graphene flakes on boron nitride nanotubes by high-temperature chemical vapor deposition

We develop a high-temperature chemical vapor deposition of highly crystalline graphene on the surface of boron nitride nanotubes (BNNTs). The growth of few-layer graphene flakes on BNNT templates was confirmed by scanning transmission electron microscopy. Based on an investigation of the effect of growth temperature and growth time on defect density, graphene with relatively high crystallinity was obtained at 1350 °C. The absence of undesirable alterations in the BNNT lattice during graphene growth was verified by multiple analyses. The high-temperature growth of heterolayers would assist in the advancement of nanodevices that coaxially combine graphene and boron nitride.