(595c) Fully Functional Large-Area Nanoporous Single Layer Graphene Membranes for Desalination and Water Purification

An ideal desalination membrane should exhibit minimum thickness to maximize water permeanceand narrow pore size distribution for efficient ionic /molecular separations. Monolayer graphene with uniform distribution of high-density of sub-nanometer pores has been considered as the perfect material offering ultra-fast water permeance and high solute rejection. However, scalable production of graphene membranes with control over sub-nanometer pores remains challenging. Here, we report the fabrication of large-area nanoporous graphene membrane for high-efficiency water desalination. The density of defects that manifest as small nanopores in graphene is significantly increased via facile and scalable oxidative etching of the graphene lattice. Novel interfacial polymerization is used to seal tears and unwanted defects in graphene. The resulting centimeter-scale monolayer graphene membranes with high-density of sub-nanometer nanopores not only allow high water permeance (upto 23 times higher than conventional membranes), but also show an excellent rejection of salt ions and organic molecules (~100% rejection). Our work provides a facile and scalable approach for atomically thin desalination and nanofiltration membranes.

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