Metal–organic frameworks grown on a porous planar template with an exceptionally high surface area: promising nanofiller platforms for CO2 separation

Abstract

Porous nanosheets made of effectively aligned zeolitic imidazolate framework-8 (ZIF-8), dubbed ZPGO, with an exceptionally high surface area (2170 m² g⁻¹) were demonstrated. This composite was prepared by growing ZIF-8s on highly porous graphene oxide (PGO) and the mixed matrix membrane with such a nanofiller showed drastically improved size-selective CO₂ transport even at very low filler concentration (0.02 wt%) especially under mixed gas conditions where both selectivity (CO₂/N₂ ∼57) and CO₂ permeability (∼163 barrer) were significantly enhanced. In addition to this, ZPGO effectively suppressed CO₂-plasticization, which indicates great potential in real operations. This new concept of nanofillers is expected to maximize the filler effect in other fields benefitting from a high surface area as well.