Ultra-permeable zeolitic imidazolate frameworks-intercalated graphene oxide membranes for unprecedented ultrafast molecular separation

Abstract

Membranes with ultrafast solvent transport for precise molecular separations are desired to reduce the energy consumption in the separation processes. Graphene oxide (GO)-based membranes have tremendous potential for precise molecular filtration. However, the construction of well-defined interlayer channels that overcome permeance-rejection trade-off is still fundamentally challenging. In this work, molecule selective GO/MOF membranes with ultrafast diffusion nanochannels were fabricated via in situ self-assembly of zeolitic imidazolate framework-8 (ZIF-8) in the GO interlayers using a facile vacuum-assisted filtration method. The obtained lamellar GO/MOF membranes with well-defined nanochannels showed unprecedented ultrafast solvent transport, with acetone and methanol permeance up to ~10,000 L m−2 h−1 bar−1 and ~6,800 L m−2 h−1 bar−1, respectively. More importantly, these membranes provided smart, selective separation performance for various binary dye mixtures with separation efficiencies higher than 95%, achieving precise separation of small organic molecules at a transport rate which is over two orders of magnitude higher than that of reported organic solvent nanofiltration membranes. Their high permeation flux as well as precise size-selective molecular recognition make them a promising candidate for energy-efficient molecular separations.