▎ 摘　　要

NOVELTY - A two-dimensional metal-organic framework film comprises metal-benzimidazole composite (I) including divalent metal e.g. zinc, cobalt and/or nickel ion as metal center ABST, and benzimidazole as organic ligand. USE - Two-dimensional metal-organic framework film is used for removing impurity gas in purification of mixed gas of hydrogen isotope and impurity gas (all claimed). ADVANTAGE - The two-dimensional metal-organic framework film has high orientation and penetration rate, and excellent membrane separation performance and selectivity. DETAILED DESCRIPTION - A two-dimensional metal-organic framework film comprises metal-benzimidazole composite (I) of formula: M2(Bim)4, where M is zinc, cobalt and/or nickel, and Bim is benzimidazole, including divalent metal ion as metal center, and benzimidazole as organic ligand. An INDEPENDENT CLAIM is included for preparation of the metal-organic framework film, which involves processing porous alumina as support, preparing a metal oxide nanoparticle layer on surface of the support, processing the nanoparticle layer using graphene oxide, immersing in a reaction solution containing benzimidazole and aqueous ammonia to react, washing, and drying.