Engineering multi-pathway graphene oxide membranes toward ultrafast water purification

Abstract

Graphene oxide (GO) membranes hold great promise in molecular separation owing to the ultrathin thickness as well as precisely controllable interlayer distance. However, the tortuous mass transport pathway along stacked nanosheets hinders the availability of high-flux GO membranes. Herein, we design multi-pathway GO membranes to afford fast water transport through in-plane and interlayer pathways. The in-plane pathway is introduced by the porous GO (pGO) nanosheets and the interlayer pathway is enlarged by intercalating hydrophilic halloysite nanotubes (HNTs) into adjacent pGO nanosheets, jointly contributing to the enhanced water permeance. Through manipulating the intercalator amount, the optimized membrane displays ultrahigh water permeance of 206.7 L m−2 h−1 bar−1 and dye rejections over 98.5%. Furthermore, the resultant membranes exhibit resistance against broad-spectrum oil-in-water emulsions. Our study can pave a facile and prospective way to fabricating high-performance two-dimensional laminated membranes.