Scalable room temperature incorporation of CO2 -selective ångström-scale pores in graphene for carbon capture

Atom-thin porous graphene membranes offer unprecedented carbon capture performance thanks to Å-scale pores that combine ultrahigh permeance with attractive selectivity. However, incorporating a high pore density has until now required high-temperature ozone oxidation, while oxidation at room temperature was found to be sluggish, limiting scalability. Herein, we uncover that graphene oxidation by ozone is constrained by mass transfer of ozone and concentration polarization from the accumulation of reaction byproduct at the surface. We overcome this bottleneck using micro channeled flow reactor that enhances mass transfer, accelerating the oxidation rate, leading to a tenfold higher pore density at room temperature. The process yields centimeter-scale membranes containing a high density of CO₂-selective pores that achieve attractive CO₂/N₂ separation performance. A brief subsequent room temperature pore expansion step further boosts performance. Our fully ambient, scalable protocol eliminates high-temperature equipment, paving a scalable route to industrial production of high-performance porous graphene membranes for carbon capture.