Manipulating gas transport channels in graphene oxide membrane with swift heavy ion irradiation

Graphene oxide (GO), a prominent two-dimensional (2D) material, has established itself as an ideal building block for separation membranes, owing to its unique laminar structures and tunable physicochemical properties. While the ultrathin nature of GO membranes is anticipated to minimize transport resistance, the convoluted mass transport pathways within laminar GO membranes generally yield moderate permeance. Here, for the first time, we explored using swift heavy ion irradiation to incorporate through transport channels in GO membranes with highly enhanced gas permeation properties. After 129Xe irradiation, characteristic ion tracks were discerned within the GO membrane cross-section. The irradiation process created disorder regions and nanopores within the laminates, and meanwhile facilitated cross-linking between the oxygen-containing groups of GO, thereby reducing the interlayer spacing and enhancing molecular sieving capabilities. The irradiated GO membranes surpassed the H2/CO2 performance upper-bound, with H2 permeance exhibiting a remarkable three-order-of -magnitude increase. This work demonstrates the feasibility of applying heavy ion irradiation to create and tune interlayer channels based on physical and chemical interactions.

Automated summary

Graphene oxide (GO) has been recognized as an ideal building block for separation membranes due to its unique laminar structures and tunable physicochemical properties. In this study, swift heavy ion irradiation was used to enhance the gas permeation properties of GO membranes by creating through transport channels. The irradiation process induced disorder regions and nanopores in the laminates, and promoted cross-linking between oxygen-containing groups of GO, resulting in reduced interlayer spacing and enhanced molecular sieving capabilities. The irradiated GO membranes exhibited a significant improvement in hydrogen permeance, surpassing the upper-bound of H2/CO2 performance. This work demonstrates the feasibility of using heavy ion irradiation to create and tune interlayer channels.