▎ 摘　　要

NOVELTY - Preparing graphene film comprises placing graphene sample of porous substrate into Faraday cage, placing into plasma vacuum cavity, pumping air pressure in cavity to less than 0.1 Pa, introducing nitrogen-containing gas source under gas flow rate of 10-200 sccm, controlling air pressure at 5-50 Pa through mass flow meter, starting plasma processor, controlling starting power at 1-20 W, and processing at 15-30 degrees C for 30-120 seconds. USE - The method is useful for preparing graphene film, which is used as proton exchange membrane. ADVANTAGE - The method is simple and low in cost, and suitable for scale-up production. Compared with the traditional high-polymer-weight film, the proton flux is higher than 2-3 orders of magnitude, and the selectivity of proton/methanol is higher than 1-2 orders of magnitude. DESCRIPTION OF DRAWING(S) - The drawing shows a flowchart illustrating the method for preparing graphene film used as proton exchange membrane (Drawing includes non-English language text).