Mesoporous metalated covalent organic framework hybrid membrane for efficient VOCs separation

Volatile organic compounds (VOCs) are pollutants detrimental to human health and the environment, necessitating the development of efficient separation technologies to support sustainable societal progress. Hybrid membranes incorporating metalated covalent organic frameworks (MCOFs) have shown great potential for VOCs separation due to the synergistic combination of polymer processability and the selective adsorption capacity of MCOFs. However, the performance of conventional MCOFs is limited by their microporous structures, which restrict molecular diffusion and accessibility to metal active sites. Herein, we have designed a mesoporous Cu(I)-metalated COF (Cu 3 L 3 -BD) with a pore diameter of 3.8 nm, which was further incorporated into poly(ether-block-amide) (Pebax) matrix to fabricate hybrid membranes (Pebax-Cu 3 L 3 -BD) for VOCs separation. The mesoporous channels facilitate improved gas transport and maximize exposure of Cu(I) coordination sites, thus enhancing the dissolution-diffusion process and improving the selectivity of Pebax-Cu 3 L 3 -BD. With a filler loading of 3 wt%, the Pebax-Cu 3 L 3 -BD exhibited optimal toluene permeance of 1.67 × 10 −6  mol μm m −2 s −1  Pa −1 and selectivity of 730, with the stability maintained over 120 h.