Reduced graphene oxide/metal oxide nanoparticles composite membranes for highly efficient molecular separation

Graphene oxide (GO) membranes play an important role in various nanofiltration applications including desalination, water purification, gas separation, and pervaporation. However, it is still very challenging to achieve both high separation efficiency and good water permeance at the same time. Here, we synthesized two kinds of GO-based composite membranes i.e. reduced GO (rGO)@MoO2 and rGO@WO3 by in-situ growth of metal nanoparticles on the surface of GO sheets. They show a high separation efficiency of ∼100% for various organic dyes such as rhodamine B, methylene blue and evans blue, along with a water permeance over 125 L m−2 h−1 bar−1. The high water permeance and rejection efficiency open up the possibility for the real applications of our GO composite membranes in water purification and wastewater treatment. Furthermore, this composite strategy can be readily extended to the fabrication of other ultrathin molecular sieving membranes for a wide range of molecular separation applications.