Demonstrating the potential of versatile single-crystal spinel magnetic CoFe₂O₄-Ti₃C₂Tₓ MXene-based hybrid platforms for multifaceted nano-level separations in gas and liquid phases

• Novel single crystal multifunctional magnetic CoFe₂O₄-Ti₃C₂ₓ MXene. • Magnetic properties, strong chemical stability, and optimized sorption sites on 2D platform. • Dual applications in nanoplastics removal from water and O₂/N₂ gas separation. • High nanoplastics removal efficiency (98.8%) across a wide pH range (2–12). • Superior O₂/N₂ separation, surpassing the Robeson upper bound. We report a multifunctional 2D-MXene-based nanocomposite that simultaneously tackles pollution in both air and water. Cationic CoFe₂O₄ nanoparticles were grafted onto anionic Ti₃C₂Tₓ sheets and aligned within a polyethersulfone matrix using magnetic field-assisted deposition. The resulting films synergically combine structural order with high stability, magnetic responsiveness, and exceptional sorption capacity. Furthermore, the material exhibits outstanding gas separation performance, with an O 2 permeability of 67 Barrer and an O₂/N₂ selectivity of 11.5, surpassing the Robeson upper bound across the temperature range from 298 to 350 K and at feed pressures from 0.1 to 2 bar. At the same time, the 2D-MXene-based nanocomposite demonstrated the ability to eliminate 98.8% of polystyrene nanoplastics from water across a wide pH range (2–12) through a synergistic mechanism involving adsorption and magnetism. These dual functionalities arise from enhanced free volume, paramagnetic interactions, and tailored interfacial chemistry. The exceptional character of MNP-MXene/PES as an efficient, versatile platform for molecular separations is underscored by its ability to provide high-performance gas separation and efficient nanoplastic remediation from water. It can undoubtedly be applied to sustainable, next-generation separation technologies.