▎ 摘　　要

NOVELTY - Manufacturing a porous graphene membrane comprises a first step of oxidizing a surface of multilayer graphene, a second step of reducing the oxidized surface of the multilayer graphene to carry out reductive etching of oxidized carbon atoms in a naturally and randomly dispersed form, and a third step of repeatedly performing a series of the first and the second steps at least twice until nanopores are formed in the multilayer graphene. USE - The method is useful for manufacturing a porous graphene membrane (claimed) which is useful in gas and ion separation and seawater desalination. ADVANTAGE - The method: is capable of manufacturing the nanoporous multilayer graphene membrane (having a pore size at an average diameter of less than or equal to 10 nm) in cost effective simplified manner when compared to conventional techniques; easily forms nanopores with a small diameter for polycrystalline multilayer graphene to manufacture a large-area nanoporous graphene membrane since a large-area graphene inevitably possesses grain boundaries; and easily forms nanodefects having a certain depth and/or nanopores penetrating a membrane in multilayer graphene by continuously applying a series of repeated (at least twice) oxidation-reduction processes to a surface of the multilayer graphene membrane, which has not been previously carried out to date.