Fabrication of 1D/2D ATP/GO-COOH membrane with low-resistance transport pathways for highly efficient separation of oil-in-water emulsion

Attapulgite/carbonylated graphene oxide (ATP/GO-COOH) composite membranes have been successfully prepared by vacuum-assisted filtration of an aqueous ATP/GO-COOH dispersion on a microfiltration substrate. Due to the interaction between the OH groups of ATPs and COOH groups of GO-COOH, ATP rods showed excellent compatibility with GO-COOH nanosheets, and the ATP mass fraction was significantly improved. The large amount of ATP can establish a fast transport channel for the diffusion of water molecules in the composite membrane. As a result, the optimum membrane gave a permeation flux with 13582 L/(m2 h), which is significantly higher than that of the pure GO-COOH membrane (2281 L/(m2 h)). In addition, the underwater superoleophobic properties of the ATP/GO-COOH composite membrane enable it to have a low oil-adhesive water/ membrane interfaces. The ATP/GO-COOH composite membrane showed good separation and separation stability for oil-in-water emulsion systems with different concentrations, pH, and oil types.