Tunable nano-wrinked channels of reduced graphene oxide membranes for molecular sieving gas separation

Abstract

Graphene oxide (GO) lamellar membranes have exhibited excellent performance in watertreatment, however there has been far less progress in the application of gas purification. Actually, exposure of the underlying graphitic framework of GO basically determines the gas permeableness of the GO lamellar membranes, which is usually neglected in the fabrication of GO lamellar membranes. Herein, we report nano-wrinkled lamellar reduced GO (rGO) sheets as gas separation membranes with oxygen-rich domains as face-to-face spacer for CO2 blockage and oxygen-poor domains for fast H2 permeation. Thanks to the excellent size-sieving mechanism of the nano-wrinkled channels, the rGO membranes exhibit high H2 permeance of 6.12 × 10−7 mol·m−2·s−1·pa−1 with exceptional selectivity of 529.9 for H2/CO2 gas mixture, surpassing the state-of-the-art ones. The membranes also show excellent stability in separation performance for H2/CO2 gas mixture under a long-term operation. Therefore, such lamellar membranes with well-tuned reduced GO nanosheets hold great potential in gas separation applications.