1D-2D intercalated network CMC@g-C3N4/IL membrane with high permeability and selectivity for the CO2 capture

The structural advantages of the membrane material itself are critical to the membrane separation performance. Two-dimensional (2D) graphitic carbon nitride (g-C 3 N 4 ) nanosheets can achieve minimal mass-transfer barrier and high gas sieving performance due to their ultra-thin thickness, inherent surface porosity and abundance of amine groups. However, the 2D g-C 3 N 4 nanosheets are prone to stacking during the self-assembly process, which reduces the membrane permeability. Based on this line, herein, we proposed a concept of construction of 1D-2D intercalated network supported ionic liquid membrane composed by one-dimensional (1D) carboxymethylcellulose ( CMC ) and g-C 3 N 4 nanosheets to overcome the low permeability of 2D graphitic carbon nitride membrane in separating CO 2 /N 2 and CO 2 /CH 4 . The as-prepared 1D-2D intercalated network supported ionic liquid gas separation membrane exhibits superior CO 2 permeance of 953.96 GPU, CO 2 /N 2 selectivity of 55.46 in separation of CO 2 /N 2 , and CO 2 permeance of 854.00 GPU, CO 2 /CH 4 selectivity of 50.62 in separation of CO 2 /CH 4 . In addition, the resulting CMC@g-C 3 N 4 /IL membrane has excellent durability. After 120 h of testing, it still has outstanding separation performance. In short, this concept in this study provides an effective modulation of molecular sieving of g-C 3 N 4 membrane for high-efficiency CO 2 capture by combination of the advantages of the 1D (CMC) and 2D (g-C 3 N 4 ) materials.