Flexible Metal–Organic Framework-Bacterial Cellulose Nanocomposite for Iodine Capture

Abstract

A flexible nanocomposite pellicle consisting of bacterial cellulose (BC) and zeolitic imidazolate framework-8 (ZIF-8) nanoparticles was prepared by sequentially soaking the BC pellicle in zinc ion and 2-methylimidazole (2-MI) solutions. The quality and quantity of ZIF-8 in situ crystallized in the pellicle was significantly improved when polydopamine, oxidatively self-polymerized dopamine, coating was applied prior on the surface of BC nanofibers. The polydopamine coating not only insulates the cellulose structure from competitive complex interaction with zinc ions employed for ZIF-8 formation but also can provide a photothermal feature to the ZIF-BC composite. ZIF-8 was well embedded inside the BC pellicle with a uniform shape and size of about 127 nm. Approximately, 70% (w/w) of the as-prepared nanocomposite (BC@Dopa-ZIF) is ZIF-8, which demonstrated a high iodine uptake capacity from vapor (1.87 ± 0.18 g I2/g) and aqueous I2/KI solution (1.31 ± 0.02 g I2/g). The iodine captured by BC@Dopa-ZIF could be ...