Method for preparing graphene

The invention discloses a method for preparing grapheme. The method uses an ion implantation technology to inject carbon ions with energy of 40 to 80 kV into a Ni film with a thickness of 200 nm grown on a SiO2/Si substrate through magnetron sputtering. The graphene is prepared by regulating amount of the ion implantation and an annealing process, with a range of implantation amount being 4*10 to 2.4*10 ions/cm and an annealing temperature being 800 to 1000 DEG C. The method is simple during the whole process, only need two processes of the ion implantation and the thermal annealing, is conducive to large-scale production of the graphene, and can control layers of the grapheme through controlling heat treatment conditions.