Zeolite imidazate framework/polyamide composite membrane and preparation method thereof

The invention discloses a zeolite imidazate framework/polyamide composite membrane and a preparation method thereof. The preparation method comprises the following steps: dissolving sodium formate, 2-aminobenzimidazole and 2-methylimidazole into deionized water so as to obtain a mixed solution; dissolving zinc salt into N,N-dimethyl formamide so as to obtain a zinc salt solution; performing mixing reaction on the mixed solution and the zinc salt solution, and performing centrifugation, washing and drying so as to obtain an NH2-ZIF-8 nano material; and soaking a substrate membrane into an organic phase solution, pouring off an organic phase solution on the substrate membrane, naturally drying in air, soaking the substrate membrane into a water-phase solution, pouring off the water-phase solution on the substrate membrane, cleaning the surface of the substrate membrane with deionized water, and drying in air at room temperature, thereby obtaining an NH2-ZIF-8/polyamide composite membrane. The prepared NH2-ZIF-8/polyamide composite membrane is used for separating gases such as CO2, N2, H2, CH4 and NOx, and the permeability and the selectivity of the membrane can be improved.