Nanostructure array assisted aggregation-based growth of a Co-MOF-74 membrane on a Ni-foam substrate for gas separation

Abstract

Metal-organic frameworks (MOFs) are promising candidates for membrane-based gas separation due to their regular crystalline lattices with relatively well-defined pore structures. To date, the preparation of integrated MOF membranes grown on porous substrates is still a major challenge. Herein, a facile aggregation-based growth method is developed to prepare a Co-MOF-74 (referred to as Co₂(dobdc), H₄dobdc = 2,5-dihydroxyterephthalic acid) membrane on a nanostructure array modified nickel (Ni) foam substrate. Ni₃S₂ nanorod arrays directly grown from the Ni-foam substrate can aggregate and effectively regulate the growth of Co-MOF-74 crystals along a given direction. The effect of reaction time on membrane growth is discussed. The resulting Co-MOF-74 membrane presents good H₂ permeance and H₂/CO₂ selectivity.