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.