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.