Direct observation of Pt-terminating carbyne on graphene

Theoretical studies predict that carbynes (single-atomic linear carbon chains) have unique properties that rival those of graphene and carbon nanotubes. However, experimental studies on carbynes are rare due to the lack of reliable and effective means of production. Here, we report a direct observation of carbyne formation and dynamics by in situ transmission electron microscopy. Using Pt atoms on graphene, we succeeded in forming and observing carbynes reproducibly. Free carbon adatoms on graphene were trapped by Pt atoms, which served as nucleation sites for carbyne formation. Each end of the carbyne chain was eventually terminated by a Pt atom, and the Pt-terminating carbyne chains exhibited a variety of straight, curved, and ringed shapes.