A novel reduced graphene oxide-based composite membrane prepared via a facile deposition method for multifunctional applications: oil/water separation and cationic dyes removal

Separation membranes fabricated with graphene oxide, a kind of two-dimensional nanomaterial, have been extensively explored to achieve the separation purpose in water treatment. However, due to the natural hydrophily and compact stacked layer structure of the GO-based membrane, which usually has a low water flux and easily damaged. In this study, RGO@SiO2 nanohybrid has been fabricated successfully, and cooperated with dopamine to synthesize novel PVDF/RGO@SiO2/PDA nanohybrid membranes via a surface deposition method. Owing to the nanochannels created by the intercalation of SiO2 between graphene layers, the composite membranes were endowed with high flux and rejection rates in separation of oil-water emulsion and dye wastewater, and the surface morphology and structure of the membrane also improved. Besides, the deposition of dopamine (DA) on the membrane surface not only could firm the composite membrane, but an effective method to obtain an extremely hydrophilic surface, meanwhile this excellent hydrophilic surface was also beneficial for membrane to obtain an outstanding oleophobicity in water environment. More importantly, the novel membranes were successfully applied for the removal of oils and cationic dye from wastewater, which also exhibited a superior anti-fouling property and sustainable stability simultaneously. In summary, the PVDF/RGO@SiO2/PDA composite membranes could have a promising potential to be used as advanced separation membranes for water purification.