Transforming zirconium-porphyrin frameworks into 2D nanosheet-assembled architectures for enhanced carbon dioxide capture

Abstract

Developing advanced sorbents for selective carbon dioxide (CO2) sequestration with minimal energy consumption remains a pivotal challenge. This study presents a novel strategy through transforming 3D bulk zirconium-porphyrin frameworks into the corresponding 2D nanosheet-assembled superstructures for enhanced CO2 capture. The hierarchical frameworks with well-organized nanosheet architectures exhibit significantly increased specific surface area from 600 m2/g to 2400 m2/g while providing kinetic benefits for gas diffusion. Compared to the adsorption behavior of the bulk counterparts, the nanosheet-assembled frameworks demonstrate a 1.5-fold increase in CO2 adsorption capacity without compromising CO2/N2 selectivity. Theoretical calculation reveals that the coordination unsaturated Zr-O clusters, electron delocalized environments both in interlayer gaps and micropores provided binding sites for CO2 capture. Our research demonstrates an adaptable structure-directed approach for the crystal engineering of metal-organic frameworks which would inspire the creation of state-of-the-art crystalline porous materials for broadened applications.

Keywords

• Metal-organic frameworks
• Hierarchical structures
• Porous crystals
• Gas separation
• Carbon dioxide