Heteroatom-Substituted Reflashed Graphene

Abstract

Flash Joule heating is an ultrafast, energy-efficient, and scalable technique used in the production of a variety of organic and inorganic compounds, including flash graphene. This technique has also been used in the production of doped graphene by flash Joule heating of amorphous carbon in the presence of heteroatom-donating compounds. Herein, we report a modified flash Joule heating technique by which graphene is formed with up to 18 atom % of the graphene lattice containing substituted heteroatoms. This is achieved by reflashing graphene in the presence of heteroatom-donating compounds, allowing this substitution to occur at lower temperatures than previously reported for flash Joule heating-synthesized doped graphene and thereby permitting much higher amounts of heteroatom insertion into the graphene lattice. We demonstrate nitrogen, sulfur, phosphorus, and fluorine atom atomic substitution into or upon the graphene lattice, as well as multiheteroatom substitution. Finally, the implementation of the nitrogen-substituted reflashed graphene into battery anodes exhibits improved performance and stability relative to unsubstituted reflashed graphene battery anodes.