Ultra-facile aqueous synthesis of nanoporous zeolitic imidazolate framework membranes for hydrogen purification and olefin/paraffin separation

An extremely simple one-step method was discovered to synthesize defect-free zeolitic imidazolate framework-8 (ZIF-8) films in aqueous solution by utilizing dopamine as a modulator. In situ dopamine polymerization is considered to inhibit the homogenous nucleation of ZIF-8 and slow down its heterogeneous nucleation, whilst the formed polydopamine facilitates the counter-diffusion growth of the ZIF-8 layer and patches the possible defects simultaneously. The designed ZIF-8 composite membrane exhibits exceptional separation performance with a H 2 /C 3 H 8 permselectivity of 6688 and a C 3 H 6 /C 3 H 8 permselectivity of 99, which can realize hydrogen and other energy-efficient continuous gas separation processes for sustainable clean energy.