▎ 摘　　要

NOVELTY - Preparing graphene comprises (1) carrying out expandable graphite expansion treatment and pulverizing to obtain expanded graphite powder; and (2) mixing and stirring expanded graphite powder with hydrogen peroxide, then degassing, then performing ultrasonic peeling, then heating to decompose hydrogen peroxide, and then drying to obtain graphene. In the step (1), particle size D50 of the crushed material is ≯ 20 μ m. In step (2), mass ratio of expanded graphite powder and hydrogen peroxide is 1:(1-100). The temperature of ultrasonic stripping is 50-100° C, and time of ultrasonic stripping is 0.5-2 hours. The temperature of thermal decomposition is 100-160° C and time of thermal decomposition is 0.5-2 hours. USE - The method is useful for preparing graphene. ADVANTAGE - The method requires shorter time, has higher stripping efficiency, simple and economical, consumes low energy, is safe, efficient and environmentally friendly, and easy to scale up. The graphene has uniform size and few defects, has excellent electrical, optical, mechanical and other properties, excellent thermal conductivity and high charged carrier mobility.