Graphene with line defect as a membrane for gas separation: Design via a first-principles modeling

A new line defect consisting of a sequence of octagons and all-hydrogen passivated pores in graphene was designed as a gas separation membrane using first-principles calculations. The all-hydrogen passivated pore produces a formidable barrier of 1.5 eV for CH4 but an easily surmountable barrier of 0.12 eV for H2. Hence it exhibits extremely high separation capability in favor of H2 among all studied species with the selectivity on the order of 1022 for H2/CH4. These results suggest that such a line-defect-containing graphene-based membrane could play a great role on numerous clean energy applications.