▎ 摘　　要

NOVELTY - Removing impurities in graphene preparation process comprises using acid washing process, liquid phase expansion treatment step and ultrasonic wave peeling off step, washing vermicular aggregates of graphene, removing metal ion in vermicular graphite layer, adding metal ion complexing agent in liquid phase expansion treatment and ultrasonic wave peeling off process, forming vermicular graphite layers free of metal ion. USE - The method is useful for removing impurities in graphene preparation process (claimed). ADVANTAGE - The method can remove metal ion impurities to provide high purity graphene.