Fast-current-driven synthesis of ultrathin ZIF-8 membrane on ceramic tube for propene/propane separation

MOF membranes are very promising in molecular separation, but it is still a challenge for industrial applications due to the complex and time-consuming synthesis. We use the fast current-driven synthesis (FCDS) method to achieve controlled growth of ZIF-8 membranes on porous graphite-coated ceramic tubes by controlling the growth time and current density. Grown for 30 min at a current density of 0.74 mA/cm 2 , the ZIF-8 membrane exhibits selectivity for C 3 H 6 /C 3 H 8 up to 63 with C 3 H 6 permeance of 6 × 10 −9 mol/(m 2 s Pa). Furthermore, the ZIF-8 membrane exhibits a pressure resistance of up to 3 bar and good stability of ~96 h. This work realizes the breakthrough of the MOF membrane synthesis via FCDS method from the frequently-used expensive and fragile anodic aluminum oxide (AAO) disc substrate to the tough ceramic tubular substrate, which broadens the road for the industrialization of MOF membranes in gas separation fields.