▎ 摘　　要

NOVELTY - A large-area graphene is prepared by cleaning a silicon substrate, vacuumizing the substrate in a chemical vapor deposition system in the presence of hydrogen, carbonizing, introducing propane to form carbide layer, heating while introducing propane and silane to obtain heterogeneous epitaxial film, cooling to room temperature gradually in the presence of hydrogen, heating, depositing nickel film on the substrate by electronic beam, placing generated carbon film sample on nickel film, introducing argon gas, annealing, and cooling to room temperature. USE - Method of preparing a large-area graphene for sealing gas or liquid. ADVANTAGE - The method prepares product having large area, smooth surface, good continuity, and low porosity. DETAILED DESCRIPTION - A large-area graphene is prepared by: (A) cleaning a silicon substrate, vacuumizing the substrate in a chemical vapor deposition system in the presence of hydrogen, carbonizing at 900-1200 degrees C, and introducing propane at a rate of 30 standard cubic centimeter per minute (sccm) for 5-10 minutes to form carbide layer; (B) heating at 1200-1300 degrees C for 30-60 minutes while introducing propane at a flow rate of 20-30 sccm and silane at a flow rate of 40-60 sccm to obtain heterogeneous epitaxial film; (C) cooling to room temperature gradually in the presence of hydrogen, heating at 700-1100 degrees C in the presence of argon gas at a flow rate of 95-98 sccm and chlorine gas at a flow rate of2-5 sccm for 3-5 minutes, and depositing nickel film having a thickness of 300-500 nm on the substrate by electronic beam at a pressure of 5x 10-4 and current of 40 mA for 10-20 minutes; and (D) placing generated carbon film sample on nickel film, introducing argon gas at a flow rate of 30-90 sccm, annealing at 900-1100 degrees C for 15-30 minutes, and cooling to room temperature. DESCRIPTION OF DRAWING(S) - The drawing is a flow chart of a method of preparing a large-area graphene (Drawing includes non-English language text).