Graphene kirigami membrane with superior theoretical permeability and adjustable selection capability

Abstract Membrane plays a central role in molecule separation and selection. However, most artificial membranes utilise a fixed passage size and only effective for limited molecule types. Here, via a large series of molecular and first-principles calculations, we reveal the potential of graphene kirigami (GK), a novel structure with nanoscale incisions on one-atom-thick graphene, which can transform into a three-dimensional structure under deformation, as an ultra-membrane for highly adjustable molecule selection and the practical fabrication feasibility of GK-like membranes using a novel selective tearing process on initially defected graphene. Facilitated by the high stretchability of GK-based membranes, we demonstrate a wide range of gas selection capability on a single membrane. The interaction energy of adsorbed gas molecule also shows that the unique geometry of the pores on GK enables a new adsorption channelling mechanism that enhances molecular separation. Compared with nanoporous graphene, the dynamic gas penetration test shows that various GK membranes are capable of 30 times higher pore-size adjustability and up to 1.5–3.4 times higher gas separation rate. The GK ultra-membrane opens new venues for numerous applications in CO2 capture and storage, water desalination, wastewater treatment, hazardous waste containment system, chemical processing, bionics, and pharmaceutical and medical devices.