Graphenization of Diamond

Diamond and graphene are the most well-studied allotropes of carbon. Both are superior in mechanical, optical, and electrical properties yet are rarely used together in combined forms. People have reported graphene–diamond heterostructures connected by van der Walls forces. However, a hybrid graphene–diamond heterostructure connected by covalent bonds would be much more robust to tackle demanding challenges such as ultrahard material machining and high-power diamond electronics. Here, we demonstrate a method of direct catalytic graphenization of diamond. Homogeneous graphene–diamond heterostructures, featured with covalent bonded interfaces, were indiscriminately grown on all diamond facets. The synthesized sp2 graphene (0001) sheets seamlessly extend from the diamond (111) sp3 lattice. Such a unique covalent-bond atomic structure gives rise to an unprecedented interfacial bonding strength of ∼150 GPa, surpassing the intrinsic strength of graphene.