▎ 摘　　要

NOVELTY - Large-piece graphene is prepared by performing layer inserting treatment on graphite powder under mild condition and presence of acid and oxidizing agent, washing with dilute hydrochloric acid to remove metal and inorganic ions, filtering, drying, and performing high-temperature treatment. USE - Preparation of large-piece graphene for electronic material and functional coating. ADVANTAGE - Large-piece graphene has complete crystal structure and large radial size, and preparation is simple, low-cost, and environment-friendly and has mild conditions and high product yield and efficiency. DESCRIPTION OF DRAWING(S) - The drawing shows a scanning electron microscope (SEM) image of large-piece graphene.