Hierarchically grown CeO2/GO on nylon filter with enhanced hydrophilicity and permeation flux for oil-water separation

Abstract

Removing contaminants from water is crucial to safeguard the global water supply chain. Water purification using membrane technology is an effective and energy-efficient solution. Graphene oxide (GO) is a promising candidate for developing advanced membranes with tunable permeation parameters. In this study, porous CeO2/GO structures are hierarchically grown on a nylon filter using vacuum coating and applied for methylene blue (MB) removal and oil-water separation. Using EDA as a crosslinker creates a durable interaction between the nylon filter, CeO2 nanoparticles, and GO. CeO2/GO-nylon filter displays better hydrophilicity, antifouling, and superoleophobicity. Increased underwater superoleophobicity is attributed to hydrophilic CeO2 nanoparticles, which increase the surface roughness of the membrane. Embedding CeO2 nanoparticles results in good hydrophilicity and assists the fast water permeation with an enhanced flux rate of up to 6451 L m−2 h−1 for pure water and 484.85 L m−2 h−1 for oil-water emulsions. The designed CeO2/GO-nylon filter exhibits excellent oil rejection rates (99%) for various oil-water emulsions. Additionally, abundant functional groups on its surface enable an efficient removal of methylene blue (99.8%) from water through electrostatic, hydrogen bonding, π-π interactions, and pore-filling mechanisms. The designed strategy provides a simple approach for creating a membrane with exceptional water purification capabilities and paves the way for highly efficient membranes for energy and environmental applications.