▎ 摘　　要

NOVELTY - Preparing double-layer graphene, comprises taking graphite, chromium trioxide and concentrated hydrochloric acid with a mol concentration of 12 mol/l at room temperature to prepare a second-order graphite intercalation compound, reacting the second-order graphite intercalation compound with oxalic acid at 60 degrees C, expanding the second-order graphite intercalation compound with the carbon dioxide and heat generated during the reaction process, and finally obtaining the exfoliated graphite i.e. the double-layered graphene. USE - The (claimed). ADVANTAGE - The method: utilizes easily available and economical raw materials and simple device; has low manufacturing cost; does not require high temperature and high pressure reaction condition and addition of other organic solvent; has high peeling yield and selectivity (more than 63%); and has simple operation and post-processing process.