Novel Halloysite Nanotubes Intercalated Graphene Oxide Based Composite Membranes for Multifunctional Applications: Oil/Water Separation and Dyes Removal

In recent years, owing to the unique properties such as high surface area and flexibility, graphene oxide (GO) has been extensively studied in the field of membrane preparation for wastewater treatment. However, GO-based membrane usually has a low water flux because of the narrow layer spacing between adjacent GO sheets. In this study, dopamine-modified halloysite nanotubes (D-HNTs) were used to increase the layer spacing of GO sheets, and then a series of novel D-HNTs/GO composite membranes were fabricated by vacuum filtration. The incorporation of D-HNTs could not only enhance the water flux of GO membrane significantly (from 9.6 to 218 L·m–2·h–1) but also improve the surface morphology and structure, which presented an underwater superoleophobic property. In addition, the wettability of membrane was further increased with the introduction of ethylenediamine in D-HNTs/GO membrane. More importantly, novel membranes were successfully applied for the simultaneous removal of oils and dyes from wastewater, which exhibited high water flux, good rejection ratio, and even superior anti-oil-fouling property. In summary, the novel GO-based composite membranes could have a bright application prospect for wastewater treatment.