▎ 摘　　要

NOVELTY - Producing graphene nano film by electrochemical exfoliation in persulfate electrolyte solution, comprises e.g. (a) introducing ammonium persulfate, potassium persulfate and sodium persulfate in distilled water to produce persulfate salt electrolyte aqueous solution containing sulfate ions, (b) washing two electrodes using distilled water or ethanol and drying at more than 60 degrees C for more than 10 minutes, and (c) impregnating two electrodes into the persulfate salt electrolyte aqueous solution, performing electrolysis by applying voltage of -1 to -20 volt on anode electrode. USE - The method is useful for producing graphene nano film and nano ink (all claimed). DETAILED DESCRIPTION - Producing graphene nano film by electrochemical exfoliation in persulfate electrolyte solution, comprises (a) introducing ammonium persulfate, potassium persulfate and sodium persulfate in distilled water to produce persulfate salt electrolyte aqueous solution containing sulfate ions, (b) washing two electrodes using distilled water or ethanol and drying at more than 60 degrees C for more than 10 minutes, (c) impregnating two electrodes into the persulfate salt electrolyte aqueous solution, performing electrolysis by applying voltage of -1 to -20 volt on anode electrode, performing electrolysis by applying voltage of 1-20 volt on cathode electrode to generate graphene nano film, and (d) separating graphene nano film from the persulfate salt electrolyte aqueous solution. The step (c) is carried out by using various kinds of gas and functionalized oxygen for separating graphene nano film from stacked graphitic-carbon layers. INDEPENDENT CLAIMS are also included for: (1) graphene nano film produced by the above method; and (2) nano ink obtained by ultrasonic dispersion of graphene nano film at a concentration of 0.5-20 mg/ml in an organic solvent.