The present invention relates to the field of
graphite materials, and in particular to an ultrafine
graphene and a preparation method thereof, wherein the preparation method comprises: 1) crushing
graphite and low-temperature ball milling to provide ultrafine
graphite powder; 2) mixing oxidant 1 with ultrafine graphite
powder for pre-oxidation; adding oxidant 2 for primary oxidation; adding intercalation agent to assist oxidation intercalation; adding oxidant 2 for secondary oxidation; filtering to provide materials and filtering out waste acid; 3) subjecting the materials to
microwave treatment to provide expanded graphite
powder; mixing the expanded graphite powder with a
solvent, ultrasonicating, filtering, and
drying to obtain ultrafine
graphene. The method of the present invention has a simple process, and the prepared nano-scale ultrafine graphite has a higher purity, and the amount of oxidant, intercalation agent, etc. used in the process is small, and the step-by-step oxidation and
microwave expansion process make the graphite layer spacing larger, which is conducive to exfoliation of
graphene, shortens the ultrasonic duration, and the number of graphene
layers finally obtained is lower; the whole process produces less waste acid, which is suitable for large-scale industrial production.