Interfacial growth of 2D MOF membranes via contra-diffusion for CO2 separation

We report a simple, effective, and environmentally-friendly method for the fabrication of high-quality 2D metal–organic framework (Ni3(HITP)2, HITP = 2,3,6,7,10,11-hexaiminotriphenylenesemiquinonate) membranes via the contra-diffusion method. The as-prepared membrane is highly continuous and compact. The membrane exhibited a CO2 permeance of 1.59 × 10−6 mol m2 s−1 Pa−1 and excellent selective permeability of CO2 over N2 and CH4. The ideal separation selectivity of CO2/N2 and CO2/CH4 is 10.2 and 6.9 respectively in single gas permeation measurements. In addition, the membrane exhibited gas separation performance with long-term stability and robustness. The new approach holds much promise for further development of the fabrication of high-quality metal–organic framework membranes for practical gas separation applications.