▎ 摘　　要

NOVELTY - Preparation of graphene comprises subjecting graphite to preoxidation treatment, and obtaining graphite; mixing graphite, preoxidizing protonic acid, and heating to obtain protonic acid intercalated graphite; mixing protonic acid intercalated graphite, organic amine and alcohol, and cooling by liquid nitrogen to obtain secondary intercalation of graphite layer; and peeling. USE - Method for preparing graphene (claimed). ADVANTAGE - The method has simple device, less resource consumption, and high quality.