Encapsulating covalent organic frameworks (COFs) in cellulose aerogels for efficient iodine uptake

•Nanoscale COFs are uniformly encapsulated in celluloses to yield hybrid aerogels.•Functionalized celluloses enable a robust encapsulation of COFs.•The hybrid aerogel keeps intact under a COF loading of up to 50 wt%.•Hybrid aerogels show high uptake performances toward dissolved and gaseous iodine.•Well-shaped aerogel columns realize dynamic iodine capture.