Biological Chitin-MOF Composites with Hierarchical Pore Systems for Air-Filtration Applications

Metal–organic frameworks (MOFs) are promising materials for gas‐separation and air‐filtration applications. However, for these applications, MOF crystallites need to be incorporated in robust and manageable support materials. We used chitin‐based networks from a marine sponge as a non‐toxic, biodegradable, and low‐weight support material for MOF deposition. The structural properties of the material favor predominant nucleation of the MOF crystallites at the inside of the hollow fibers. This composite has a hierarchical pore system with surface areas up to 800 m2 g−1 and pore volumes of 3.6 cm3 g−1, allowing good transport kinetics and a very high loading of the active material. Ammonia break‐through experiments highlight the accessibility of the MOF crystallites and the adsorption potential of the composite indicating their high potential for filtration applications for toxic industrial gases. Sponge bag: A composite material is formed from a metal–organic framework (MOF) and a chitin biopolymeric network extracted from a marine sponge. The inner surface functionalities of the biomatrix cause the MOF HKUST‐1 (Cu3BTC2) to crystalize inside the hollow chitin fibers, resulting in a hierarchical pore system with a surface area of up to 800 m2 g−1. The composite shows a high affinity for toxic industrial gases such as NH3.