Structure regulation of two-dimensional lamellar NH2-UIO-66@MXene membrane for efficient H2/CO2 separation

Two-dimensional membranes are considered the next generation separation membrane with great application potential due to their excellent separation performance, good mechanical strength and thermal stability compared with traditional membrane materials. In this work, the flexible NH 2 -UIO-66@MXene membrane was successfully prepared for gas separation by loading NH 2 -UIO-66 particles onto Ti 3 C 2 nanosheets based on an in-situ growth strategy. A LiF-HCl mixed solution was used as the etchant to obtain the Ti 3 C 2 nanosheets. The loading of NH 2 -UIO-66 particles can regulate the interlayer spacing of Ti 3 C 2 nanosheets, improving the specific surface area of Ti 3 C 2 and the adsorption capacity for specific gases. The -NH 2 group in NH 2 -UIO-66 enabled preferential adsorption of CO 2 over H 2 , and the CO 2 molecules adsorbed in the channel can even block the molecules passing through, increasing the resistance of CO 2 diffusion. As a result, the NH 2 -UIO-66@Ti 3 C 2 hybrid membrane realizes the selective separation of H 2 /CO 2 mixed gas, and the separation selectivity is as high as 155. The gas separation selectivity and permeation of the final prepared NH 2 -UIO-66@MXene were enhanced and exceeded the upper limit of Robeson upper bound (2017).