Pore Tuning of Metal-Organic Framework Membrane Anchored on Graphene-Oxide Nanoribbon

Abstract

Although the pore structures and gas transport properties of metal-organic frameworks (MOFs) have been tuned mainly by modifying the framework building blocks, a pore-tuned zeolitic imidazolate framework (ZIF)-8 layer is directly grown on graphene oxide nanoribbons (GONR)-treated polymer substrate. Oxygen-containing functional groups and GONR danglingcarbon bonds facilitated the spontaneous growth of ZIF-8 oriented to the (100) grain on the GONR surface and also enhanced the rigidity by strongly anchoring the ZIF-8 layer by metal-carbon chemisorption. Gas permeation and molecular simulation results confirmed that the effective aperture size of ZIF-8 is adjusted to 3.6 ?. As a result, ultrafast H2 permeance of 7.6 × 10?7 mol m?2 Pa s is achieved while blocking large hydrocarbon molecules. In particular, the membrane showed exceptionally enhanced hydrogen selectivity for the mixture separation than ideal selectivity, owing to the competitive transport between H2 and large hydrocarbon molecules, and the separation performance surpassed those of ZIF membranes previously fabricated on polymeric supports.