▎ 摘　　要

NOVELTY - Preparation of a large-sized graphene involves mixing (a) a graphite with a concentrated sulfuric acid so as to carry out chemical intercalation and mechanical peeling resulting in a mixed solution, ultrasonically treating (b) the mixed solution to obtain a treated solution comprising an upper graphene and a lower concentrated sulfuric acid solution, separating (c) graphene from the concentrated sulfuric acid solution, and washing (d) the graphene using water, filtering and drying. USE - Preparation of large-sized graphene (claimed). ADVANTAGE - The method enables efficient and environmentally-friendly preparation of large-sized graphene, and ensures excellent stripping effect. Sulfuric acid used during the process can be repeatedly utilized.