(256b) Graphene-Derived Membranes for Gas and Liquid Separation

Although graphene is a gas-impermeable, if pores could be properly engineered in graphene, its atomic thickness, and high mechanical strength would yield the thinnest-yet molecular filter. However, scalable fabrication of graphene-based membranes with subnanometre pores and high porosity is a great challenge. Here we report that gas molecules can diffuse through defective pores and slit-like interlayers in large-area, few-layered graphene or ultrathin graphene oxide (GO) membranes with nanometric thickness, and that gas diffusion through these membranes can be tuned by randomly stacking, engineering channels, and creating pores. These results are entirely counterintuitive because graphitic layers are usually believed to pose an effective gas barrier. Particularly, ultrathin GO membranes showed highly CO₂ permeable properties due to the strong affinity between CO₂ and GO, and are therefore excellent candidate materials for CO₂ separations. Our findings could potentially be extended to the nanomembranes fabrication for fast, selective mass transport of gases and liquids.