▎ 摘　　要

NOVELTY - Graphene is prepared by mixing soluble salt of divalent metal ion, soluble salt of trivalent metal ion, soluble salt of alkyl anion and carbon source with deionized water to prepare mixed salt solution; mixing mixed salt solution with alkali solution to obtain layered dihydroxy composite metal oxide having intercalated structure; calcining layered dihydroxy composite metal oxide for 5-3 hours at 700-950 degrees C; and adding calcined product in 5% hydrochloric acid solution, centrifuging, separating, and washing lower layer deposit with deionized water to obtain the graphene. USE - Method of preparing graphene (claimed). ADVANTAGE - The method has wide source of raw materials, is stable and safe, and allows carbon source to grow into graphite in two-dimensional limit domain space, thus synthesizing graphene with different layers. DETAILED DESCRIPTION - Preparation of graphene comprises: (A) mixing soluble salt of divalent metal ion, soluble salt of trivalent metal ion, soluble salt of alkyl anion and carbon source with deionized water to prepare mixed salt solution; (B) mixing the mixed salt solution with alkali solution under protection of nitrogen at 60-80 degrees C and crystallizing for 6-10 hours to obtain suspension, filtering, then washing filter cake with deionized water until pH value is 7-7.5, and drying the filter cake for 6-12 hours at 50-60 degrees C to obtain layered dihydroxy composite metal oxide having intercalated structure; (C) calcining the layered dihydroxy composite metal oxide for 5-3 hours at 700-950 degrees C under protection of inert atmosphere or reducing atmosphere to obtain calcined product, where the inert atmosphere is nitrogen or argon gas atmosphere, and the reducing atmosphere is hydrogen atmosphere; and (D) adding the calcined product in 5% hydrochloric acid solution at solid to liquid ratio of 2-7 g/L, centrifuging for 5-2 hours at 5000-9000 revolutions/minute, separating, washing lower layer deposit with deionized water until pH value is 6.5-7 to obtain the graphene.