Designing GO Channels with High Selectivity for CO2/N2 Separation via Incorporating Metal Ions

Graphene oxide (GO) membranes holds great potential for high-performance CO2 capture. Aiming at enhancing the CO2 separation performance and structural stability of GO membranes, functionalizing GO channels with metal ions confers a promising strategy. In this study, we reported the fabrication of metal ion-incorporated GO membranes with remarkably improved CO2 /N2 separation performance. The metal ions within GO channels contribute to facilitating CO2 transport, decreasing N2 solubility, hindering N2 diffusion, and form multiple interactions with GO nanosheets. After introducing Mg2+ ions, the CO2 /N2 separation factor of GO membrane is remarkably increased from 4 to 48.8 with the CO2 permeance increases 1.5 times. Moreover, the separation performance of the GO-Mg2+ membranes shows an excellent long-term stability owing to the structural robustness. This study could provide insights into the regulation of the microstructure of metal ion-functionalized GO membranes for highly selective transport of specific molecules.