Gas permeation through double-layer graphene oxide membranes: The role of interlayer distance and pore offset

Abstract Hierarchically stacked graphene oxide (GO) membranes have sparked considerable interest due to their prominent separation performance; however, the underlying separation mechanisms remain elusive. In this study, we conducted molecular dynamics (MD) simulations to explore the role of interlayer distance and pore offset in gas (H 2 , CH 4 , N 2 and CO 2 ) permeation through double-layer GO membranes. Gas permeance is found to increase with the interlayer distance and pore offset until the interlayer distance exceeds a critical value. With elongating the interlayer distance and pore offset, a sieving effect occurs to overcome preferential adsorption and dominates the transport in mixed H 2 /CO 2 , resulting in selective permeation shifting from CO 2 to H 2 . This simulation study provides mechanistic insight into gas permeation through layered GO membranes, and would facilitate the design of new GO membranes for high-performance gas separation.