Graphenesynthesisbychemical-vapor-deposition(CVD)hasattractedgreatinterest. Asthesubstratesforgraphene growth, copper has become a common choice because its capacity could produce high-quality and uniform monolayer graphene. Morphology and surface conditions of the copper foil have great influence on the quality of the graphene grown on it. Here we report a rapid and effective copper pre-treatment method to improve the quality of graphene. After a pre-etching in 1 mol/L Fe(NO3)3aqueous solutions for 90 s, t...