▎ 摘　　要

NOVELTY - Producing graphene comprises: (a) providing a mixture (50) of graphite in a solvent; (b) subjecting the mixture to sonication at at least one frequency of 15-30 kHz; and (c) subjecting the mixture to sonication at at least one frequency of 50-250 kHz. USE - The method is useful for producing graphene (claimed), which is used as an additive for polymers including polyethylene and polystyrene. ADVANTAGE - The method provides graphene: in high yield at relatively less time; and in a cost efficient manner. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for graphene obtainable or obtained by the method. DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of apparatus for performing the method. First reactor (10) Second reactor (20) Holding tank (30) Control unit (40) Mixture (50)