Preparation of High Stability Graphene Oxide/Zinc Oxide Composite Membrane via Vacuum Filtration for Separation of Methylene Blue from Aqueous Solution

In the present work, an excellent stable low graphene oxide/zinc oxide (LGO‐ZnO) composite membrane based on LGO nanosheets and ZnO nanonods has been successfully synthesized by vacuum filtration. The resultant graphene oxide nanosheet with a low degree of oxidation (LGO) was successfully prepared with the C/O ratio of 4.8 after stripped and oxidized. Importantly, the characterization results also demonstrated that ZnO nanorods were successfully intercalated into adjacent LGO nanosheets, rendering enlarged mass transfer channels, elevating hydration capacity and creating hierarchical nanostructures of membrane surfaces. Meanwhile, the stability of LGO‐ZnO composite membrane was enhanced obviously due to intercalation of ZnO nanorods, which was much more stable than that of LGO in aqueous solution. And it also exhibited outstanding permeation and separation performance for the water and various dyes solution system (with different concentration, volume or dye species), respectively. Accordingly, the permeate fluxes exhibited a drastic increase from 73 L/m2/h for LGO membrane to 1313 L/m2/h for LGO‐ZnO membrane. All the above results suggested that LGO‐ZnO membrane with high stability, high water permeability and favorable separation efficiency could be used as the great prospects membrane materials in separation of dyes from aqueous solution. The graphic displayed transmission electron microscope images of zinc oxide (ZnO) nanorods (a) and low degree oxidation graphene (LGO) nanosheets (b), scanning electron microscopy images of surface (c) and cross‐sectional (d) of LGO‐ZnO membrane, respectively. A short rod‐like structure of ZnO nanorod and a wrinkled corrugation of LGO membrane were clearly performed. After the intercalation of ZnO nanorods, the surface of LGO membranes were evenly distributed with interpenetrating nanostructure, which also presented the well layered membrane structure.