MOF Fibrous Membranes with Efficient Gas Transfer Channel for Carbon Dioxide Capture

Metal-organic frameworks (MOFs), known for their high surface area, adjustable pore structure, and ease of functional modification, have attracted considerable interest for carbon dioxide (CO₂) capture. Nevertheless, their practical use is hindered by their powdered form, which results in limited mechanical strength and a reduced gas transport performance. In this study, an effective approach is presented for developing three-dimensional UiO-66-NH₂/polyacrylonitrile (PAN) interconnected networks to serve as efficient gas transport pathways, thereby enhancing CO₂ adsorption capabilities. The developed hierarchical pores benefitted the prepared fibrous membranes (FMs) of UiO-66-NH₂/PAN, which showed a high MOF loading mass of 70 wt %, a high specific surface area of 269.68 m²/g, a high CO₂ adsorption capacity of 3.17 mmol/g at 298 K, an excellent CO₂/N₂ selectivity of 36, and stable recyclable regeneration capability. Gas dynamic breakthrough results showed that UiO-66-NH₂/PAN FMs could efficiently separate CO₂ from N₂. Furthermore, the potential gas binding sites were studied using density functional theory calculations, which indicated that the micropore channels of UiO-66-NH₂ preferably adsorbed CO₂ with excellent affinity. This study presents a prospective direction for developing MOF FMs with hierarchical pores to enhance efficient CO₂ capture.