Method for preparing graphene efficiently

The invention discloses a method for preparing graphene efficiently. The method comprises the following steps: (1) respectively weighing soluble inorganic salt and/or soluble organic matter and expanded graphite for later use according to the mass ratio of the soluble inorganic salt and/or the soluble organic matter to the expanded graphite of 10:1 to 200:1, wherein the expanded graphite serves as a raw material; (2) adding the soluble inorganic salt and/or the soluble organic matter and the expanded graphite into distilled water, heating, mixing uniformly until the soluble inorganic salt and/or the soluble organic matter are dissolved completely, placing into a drying box until the water is volatilized completely to obtain the mixture of the expanded graphite and the inorganic salt and/or the organic matter, placing the mixture into a ball-milling tank and performing ball milling; and (3) separating ball-milling products, washing with distilled water for 3 to 5 times, performing suction filtration and drying to obtain the graphene. The graphene is prepared according to the physical method. The method is simple and practical, has no specific requirement on equipment, is low in cost, high in efficiency, pollution-free and easy to popularize and use, and solves the problems of high cost, low efficiency, low quality and the like in the conventional preparation technology for the graphene.