▎ 摘　　要

Large scale and homogenous bernal-stacked bilayer (AB-stacked) graphene is a promising 2D functional material due to its distinct electronic properties. As motivated by some evidence, the continuous carbon radicals (e.g., CH3) can greatly contribute to the nucleation and growth of second layer graphene film; thus, overcoming the self-limited catalysis regime of metallic Cu surface by conventional chemical vapor deposition. Herein, a two-step reaction system is designed to facilitate more continuously supplying reactive intermediate for the second layer growth of graphene. With this strategy, monolayer and AB-stacked bilayer graphene films can be controllably grown by simply tuning the confined amount of predeposited amorphous carbon (-C) under atmospheric pressure rather than low pressure or vacuum. This approach opens a straightforward way to grow 2D materials by managing the surficially catalytic kinetics in the two separated reaction units.