Facile synthesis and biomimetic amine-functionalization of chitosan foam for CO₂ capture

A high-performance biomass-based adsorption materials could be the promising trend for CO₂ capture and storage technology. However, the direct application of biomass-based porous materials as a CO₂ adsorbent with enhanced performance is an emerging issue. Herein, a facile synthesis and a biomimetic strategy were combined to prepare amine-functionalized chitosan foam for CO₂ capture, and then a porous biomass is achieved for the application on the environment protection field. Firstly, the chitosan foam was synthesized by the emulsion-templating method at room temperature. Depended on stabilizing n-octane in the chitosan hydrogel with Span 80, a tunable three-dimensional network porous structure was obtained. Subsequently, co-deposition with dopamine (DA) and polyethyleneimine (PEI) was applied to load abundant amine content on the surface of chitosan foam and thereby improving CO₂ adsorption capacity. Finally, the as-prepared amine-functionalized chitosan foam exhibited the impressive adsorption capacity of 3.59 mmol/g at 333 K and atmospheric pressure, and the better adsorption selectivity and stability. The results extend the preparation approach of biomass porous materials, and also its application in CO₂ adsorption technology.