(401ak) Gas Separation from Intrinsic Defects of Single Layer Graphene
The gas permeation experiments with four gases (H2, He, CH4, and CO2) at variable temperatures (25-200 Â°C) were conducted to study the transport properties of the intrinsic defects of atom-thick graphene film. Resulting permeance of CH4 and CO2 were 6 and 16 GPU, respectivelyat 200 °C. Moreover, He/CH4 ideal gas selectivity was as high as 29 with He permeance of 183 GPU at 200 °C. Interestingly, we also observed H2/CO2 selectivity (8.8) with H2 permeance of 137 GPUat 200 °C, indicating that average size of nanopores in graphene was somewhat smaller than that of the kinetic diameter of CO2. The permeance increased with temperature, indicating molecular transport was in the activated transport regime. This high gas selectivity observed from a 1 mm2 large graphene membrane is first proof-of-principle report on gas separation from large-scale single-layer graphene film.
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