Self-converted fabrication of a Ni-MOF-74 tubular membrane from nickel-based nanosheets for butanol dehydration by pervaporation

Abstract

Metal–organic frameworks (MOFs) with uniform pore size and rich functionality are promising candidates for membrane materials. However, the relatively weak stability of MOFs inhibits their applications in liquid separation. Herein, we proposed a simple and efficient strategy for the preparation of a well-intergrown and stable Ni-MOF-74 tubular membrane by the self-conversion of a nickel-based nanosheet layer (Ni-NSL). In this method, the Ni-NSL not only serves as a metal source for promoting heterogeneous nucleation to achieve high-quality Ni-MOF-74 membranes, but also acts as an inorganic linker between the support and membrane for enhancing membrane stability. Owing to the existence of the Ni-NSL, a thin Ni-MOF-74 membrane with a thickness of ca. 2.5 μm was obtained. The membrane exhibited excellent pervaporation performance with a separation factor of 1094 and a flux of 1.75 kg m⁻² h⁻¹ for n-butanol dehydration. Furthermore, the as-prepared Ni-MOF-74 membrane has good stability for 120 h of the separation of n-butanol/water. Therefore, the Ni-MOF-74 membrane by the self-conversion strategy is very promising for pervaporation separation of n-butanol.