Fullerene-Tailored Graphene Oxide Interlayer Spacing for Energy-Efficient Water Desalination

Graphene oxide (GO) has attracted significant research interest because of its unique properties in ion sieving and water desalination. Nevertheless, it is a great challenge to tune and fix the interlayer spacing of GO sheets at the range of 1 nm. Herein, we report a strategy adjusting the interlayer spacing of GO laminates by grafting C60 molecules on the surface of GO sheets via lithiation reaction, and a fixed interlayer spacing of 1.25 nm can be achieved. In order to increase the effective area for water desalination, cross-sectional filtration has been applied by encapsulating GO/C60 membranes via epoxy. The as-prepared GO/C60 membrane obtains a high water flux up to 10.85 L h–1 m–2 bar–1. Meanwhile, subjecting to the electrostatic exclusion and steric effect, the rejection rate for NaCl can reach 89.66%, which is sufficient to purify brackish water into drinkable water. In addition, this GO/C60 membrane requires low pressure (<5 bar) for operation and exhibits long-term stability, which provides a great potential for energy-efficient water desalination.