▎ 摘　　要

NOVELTY - Preparing high quality large-sized graphene comprises (1) mixing original graphite and potassium hydroxide in the mass ratio of 1:5-15, and grinding; (2) placing the powder obtained in the step (1) in crucible, placing in tubular furnace, heating to 800 degrees C for 60 minutes in argon atmosphere, and cooling to room temperature to obtain potassium hydroxide-etched graphite; (3) adding 1 g etched graphite obtained in the step (2) into each 5 ml hydrogen peroxide solution (30%) and ultrasonically dispersing for 4-10 minutes, and subjecting the ultrasonically dispersed etched graphite to microwave irradiation for 30-120 seconds to obtain graphene aggregates; and (4) ultrasonically dispersing the graphene aggregate obtained in the step (3) in an alcohol having purity of 99%, drying to obtain high quality graphene having maximum size of 150 mu m2. USE - The method is useful for preparing high quality large-sized graphene. ADVANTAGE - The method: is simple and economical; does not require any strong oxidizing agent and strong acid; and greatly reduces pollution and damage to environment. The graphene: has flat appearance with maximum size of 150 mu m2 and maximum conductivity of 2x 105 S/m.