A novel 3D covalent organic framework membrane grown on a porous α-Al₂O₃ substrate under solvothermal conditions

A novel approach to grow a 3D COF-320 membrane on a surface-modified porous α-Al₂O₃ substrate is developed. A compact and uniform COF-320 membrane with a layer thickness of ∼4 μm is obtained. This is the first reported 3D COF functional membrane fabricated successfully on a common porous α-Al₂O₃ ceramic support. The gas permeation results indicate that the gas transport behavior is mainly governed by the predicted Knudsen diffusion process due to the large nanopores of 3D COF-320.