In Situ Construction of Covalent Organic Framework Membranes on Polyacrylonitrile Nanofibers for Carbon Dioxide Capture

Addressing the pressing and significant issue of reducing greenhouse gas emissions in our society, it is crucial to develop environmentally sustainable materials for carbon dioxide adsorption. In this work, we propose a straightforward and effective method, that is, in situ growth of covalent organic frameworks (COFs) on a polyacrylonitrile (PAN) nanofiber substrate using a reversible polycondensation termination technique and successfully prepare flexible COF nanofiber membranes (PANm@BTCA-TPB and APANm@BTCA-TPB COF) for highly efficient capture of CO2. The resulting composite of PAN@COFs comprises numerous nanofibers enveloped by well-defined porous COFs spheres (∼500 nm) that possess a stable crystal structure, abundant functional groups, and excellent stability. Additionally, these composites demonstrate promising capabilities in efficient carbon dioxide capture and have potential for the separation of carbon dioxide and methane. The proposed approach of in situ growth of COFs on nanofibrous membranes is not only applicable to other COF materials derived from Schiff bases but also provides an effective strategy for constructing flexible COF-based membranes that can meet the requirements of various application scenarios.