Effect and Mechanism of Hydrogen-Assisted Sulfur Intercalation for Decoupling Graphene from Cu(1 1 1) Substrate: A First-Principles Study

Two different mechanisms, namely direct S intercalation at the zigzag edge of graphene and H-assisted S intercalation at the armchair edge of graphene, were determined theoretically to exfoliate the CVD-grown graphene from Cu(111) substrate. The formed CuS intercalation can significantly improve the exfoliation properties of graphene, and hinder the electron transfer from the substrate to graphene, leading to the charge-neutral free-standing graphene on Cu substrate.