Nanometer-Thick Supported Graphene Oxide Membrane for CO₂ Capture

Large-scale CO2 capture through membrane separation is the only viable method for cost-effective emission reduction. However, the fabrication of CO2 separation membranes with sufficient flux and selectivity in the presence of water vapor and an acceptable cost still presents an almost insurmountable challenge. In this work, it is shown that nanometer-thick supported graphene oxide (GO) membranes have the potential to meet this challenge. Fifteen-nanometer-thick GO membranes can be prepared through deposition of a dispersion by spin-coating, drying and rapid thermal processing (RTP). The RTP treatment results in the formation of selective CO2 transport pathways. The effect of any remaining nonselective defects is minimized by an application of a thin (<50 nm) layer of polydimethylsiloxane (PDMS). The optimized membranes showed CO2 permeance (flux/pressure difference) of 5.7 × 10–8 [mol/(m2·s·Pa)] (183 GPU) and CO2/N2 selectivity of 259 at 57 °C in a wet mixture of 20% CO2 and 80% N2.