Free-Standing Graphene Oxide-Palygorskite Nanohybrid Membrane for Oil/Water Separation.

Graphene oxide (GO) is an emerging kind of building block for advanced membranes with tunable passageway for water molecules. To synergistically manipulate the channel and surface structures/properties of GO-based membranes, the different building blocks are combined and the specific interfacial interactions are designed in this study. With vacuum-assisted filtration self-assembly, palygorskite nanorods are intercalated into adjacent GO nanosheets, and GO nanosheets are assembled into laminate structures through π–π stacking and cation cross-linking. The palygorskite nanorods in the free-standing GOP nanohybrid membranes take a 3-fold role, rendering enlarged mass transfer channels, elevating hydration capacity, and creating hierarchical nanostructures of membrane surfaces. Accordingly, the permeate fluxes from 267 L/(m2 h) for GO membrane to 1867 L/(m2 h) for GOP membrane. The hydration capacity and hierarchical nanostructures synergistically endow GOP membranes with underwater superoleophobic and low oi...