▎ 摘　　要

NOVELTY - Preparing large-area graphene comprises e.g. reaction furnace containing molten solvent, heating the solvent in the reaction furnace to form high temperature region and low temperature region has temperature difference is 20 degrees C, mixing carbon source and the solvent in high-temperature region to form initial solution, flowing of initial solution from high temperature region to low-temperature region to form supersaturated solution, precipitating on surface of saturated solution to form large-area graphene, where the large-area graphene layer number is less than 20. USE - The method is useful for preparing large-area graphene (claimed). ADVANTAGE - The method produces more perfect graphene plane of large area graphene. DETAILED DESCRIPTION - Preparing large-area graphene comprises reaction furnace containing molten solvent, heating the solvent in the reaction furnace to form a high temperature region and a low temperature region has a temperature difference is 20 degrees C, mixing carbon source and the solvent in the high-temperature region to form an initial solution, flowing of the initial solution from the high temperature region to the low-temperature region to form a supersaturated solution, precipitating on a surface of the saturated solution to form a large-area graphene, where the large-area graphene layer number is less than 20 and has a La of 1-1000 mu m diameter, the La is a value obtained by Raman spectroscopy.