▎ 摘　　要

NOVELTY - Method for preparing powdered graphene involves (i) passing inert gas into the microwave plasma chemical vapor deposition system to generate plasma and (ii) passing a carbon source-nucleation density inhibitor mixed gas into the microwave plasma chemical vapor deposition system to perform vapor phase growth of graphene powder and directly collecting graphene powder in the exhaust gas. USE - Method for preparing powdered graphene. ADVANTAGE - The method is simple, pure and effective, realizes the regulation of the graphene size in the gas phase for the first time, and can control the appropriate increase or decrease of the graphene size, can directly obtain graphene quantum dots in the gas phase and has high crystallinity.