An ultrafast water transport forward osmosis membrane: porous graphene

Abstract

As an emerging technology, forward osmosis (FO) has shown great promise in energy production from the mixing of fresh water and seawater in estuaries. However, the power density levels of the present commercial FO membranes hinder their practical applications in power generation due to the requirement for extremely large areas of membrane. Here, we use functionalized porous-single-layer graphene as a FO membrane and study the transport performances of the membrane using molecular dynamics simulation. For the FO system using fluorinated porous graphene (pore-diameter 11.7 Å, porosity 10%), with an excellent performance for salt rejection, the water flux is 28.1 L cm⁻² h which is about 1.8 × 10⁴ times higher than that of a typical cellulose triacetate membrane. Such high water flux will certainly bring about a very high power density in pressure retarded osmosis power generation. This work may generate potential opportunities for functionalized graphene in FO power generation, seawater desalination and so forth.