Metal–organic framework-immobilized track-etched membrane with PVC nanofiber mats for carbon dioxide capture

The increasing concentration of carbon dioxide in the atmosphere is a major cause of climate change, necessitating the development of efficient adsorbents for CO₂ capture. Traditional methods, such as adsorption using amines and cryogenic separation, are constrained by high energy consumption, equipment corrosion, and solvent degradation. Membrane technology can help overcome some of the problems associated with these traditional methods. Track-etched membranes (TeMs), with their unique properties, have been used as substrates for the preparation of composite membranes to capture CO₂. In this study, we synthesized HKUST-1 metal-organic frameworks (MOFs) by the solvothermal method and incorporated them into PVC nanofibers by electrospinning. The nanofibers were then deposited on PET TeMs. The secondary decoration of HKUST-1 was performed to increase the MOF concentration. The integration of MOFs improved adsorption capacity due to their high surface area and porosity. The obtained membranes were characterised by FTIR, XRD, SEM-EDX, BET, TGA, and contact angle measurements. The composite membrane exhibited a BET surface area of 135.26 m² g^-1. The contact angle of the membrane was 95° ± 9°, indicating a hydrophobic nature. The PVC/HKUST-1(SD)@PET TeM was shown to have a CO₂ adsorption capacity of 1.48 mmol g^-1 at 25 °C, with efficient regeneration properties. The CO₂ capturing capacity retains 94% of the initial value after 12 adsorption-desorption cycles. These results demonstrate the potential of the obtained membrane as an efficient, regenerable and adsorptive membrane for CO₂ capture.