Reversed thermo-switchable molecular sieving membranes composed of two-dimensional metal-organic nanosheets for gas separation

by Dan ZHAO
Reversed thermo-switchable molecular sieving membranes composed of two-dimensional metal-organic nanosheets for gas separation

We pioneer a smart 2D MOF membrane for H2/CO2 separation.

We prepared nm-thick two-dimensional (2D) membranes composed of metal-organic framework (MOF) nanosheets demonstrating reversed thermos-switchable molecular sieving gas separation performance. The MOF nanosheets were exfoliated by freeze-thaw approach in suitable solvent systems. In order to remove the nanoparticles or small fragments, we proposed a solvent-selective sedimentation approach for size fractionation and collection of ultra-large MOF nanosheets with lateral size of more than 20 mm. The exfoliated and purified MOF nanosheets were well-aligned into membranes with various thicknesses, wherein the challenges were elucidated with offered solutions that will be helpful for the fabrication of other 2D MOF membranes. The membranes derived from well-aligned MOF nanosheets demonstrated an unprecedented reversed thermos-switchable H2 permeation, which can be attributed to the structural flexibility of the MOF that has yet to be observed in other inorganic membranes. This work sheds light on the tailored synthesis of smart 2D membranes with wide applications in clean energy and environmental sustainability.

This work has been published in Nature Communications (Nat. Commun.) on Feb 16, 2017 (doi: 10.1038/ncomms14460)


Corresponding author(s): Dan ZHAO (chezhao@nus.edu.sg)
Corresponding authors(s) Webpage: http://cheed.nus.edu.sg/stf/chezhao/home.html