Graphene preparation method

The invention belongs to the technical field of carbon material preparation, and discloses a graphene preparation method based on a liquid phase stripping method and a hydrothermal method. The graphene preparation method comprises the following steps: adding powdered graphite and water into a reaction kettle; sealing, then stirring, heating to a reaction temperature, keeping constant temperature, continuously stirring and reacting; after ending reaction, cooling, taking out a mixed solution in the reaction kettle so as to carry out centrifugal separation, wherein solids at a lower layer are unreacted powered graphite, and supernatant liquid is graphene dispersion liquid; and carrying out centrifugal separation on the graphene dispersion liquid so as to obtain solids, namely graphene. According to the graphene preparation method, water is used as a solvent so as to overcome the shortcomings that an organic solvent is high in boiling point and difficult to remove and has toxicity, or as Hansen solubility parameters of the organic solvent cannot meet the solubility parameters of graphene, the concentration of the dispersion liquid is relatively low. The yield of the prepared graphene is high; the prepared graphene has very few defects and is very low in oxygen content; and the intrinsic electrical property of the graphene is maintained.