CO2-selective zeolitic imidazolate framework membrane on graphene oxide nanoribbons: experimental and theoretical studies

초록

A CO2-selective ZIF-type membrane was fabricated by growing a ZIF-8 layer on a graphene oxide nanoribbon (GONR)-coated polymeric substrate. Owing to the strong anchoring effect of GONRs to the ZIF-8 crystal, the pore window of the ZIF-8 layer can be tuned with a molecular cut-off range of 3.4-3.6 angstrom. The prepared membrane showed a CO2 permeance of 7.8 x 10(-9) mol m(-2) Pa-1 s(-1) with a CO2/CH4 selectivity of 27, which surpassed the CO2/hydrocarbon separation performance of most reported ZIF-type membranes and were comparable to those of ZIF-94 type membranes known to be effective for CO2 extraction. Multiscale computational simulation demonstrated that the CO2 selective permeation of the ZIF-8/GONR membrane was attributed to the low diffusivity of CH4 in the rigid ZIF-8 framework. The obtained experimental and computational results illustrate that the pore-tuned ZIF-8 framework can be effectively used for CO2 separation by adjusting the aperture size.

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