The synthesis of graphene and hexagonal boron nitride (hBN) hybrid sheets has been achieved using a two-step chemical vapor deposition (CVD) process. Individual grains of single-layer graphene are grown from methane, and hBN is, then, synthesized from ammonia borane on the same copper (Cu) foil. Optical absorption and Raman measurements reveal that the hBN is formed on the bare surface of Cu foil and the graphene grains play a crucial role as an inactive protective layer of Cu foil for the ammonia borane CVD. Furthermore, the hBN growth is found to be initiated preferentially by the edge of graphene grains.

The crystal orientation of epitaxially grown hexagonal boron nitride (hBN) monolayers from graphene edges was investigated. Low-energy electron microscopy observations reveal that the orientation of individual hBN grains is dependent on the direction of the templated zigzag edges of graphene. Furthermore, the triangular atomic defects in hBN were used to confirm the orientation of epitaxial hBN through high-resolution transmission electron microscopy observations. The results indicate that the orientation of epitaxially grown hBN is determined by the formation of carbon–boron bonds at the graphene/hBN interface, which provides a promising way of producing uniform interface structures and orientation-controlled hBN grains.