Enhancing CO Oversaturation in the Confined Water Enables Superior Gas Selectivity of 2D Membranes.

Due to the global demands on carbon neutralization, CO separation membranes, particularly those based on two-dimensional (2D) materials, have attracted increasing attention. However, recent works have focused on the chemical decoration of membranes to realize the selective transport, leading to the compromised stability in the presence of moisture. Herein, we develop a series of 2D capillaries based on layered double hydroxide (LDH), graphene oxide, and vermiculite to enhance the oversaturation of CO in the confined water for promoting the membrane permselectivity.