A facile bionic strategy towards Gd (III)-imprinted membranes via interlaced stacking of one-dimensional/two-dimensional nanocomposite materials

Abstract

Rapid development of rare earth industry has led to an increasing demand for highly purified rare earth elements (REEs). The combination of ion-imprinted technique (IIT) and membrane separation technique (MST) is recently regarded as a promising strategy for selectively separating specific ions from multiple REEs. In this work, a facile bionic strategy for preparation of Gd (III)-imprinted membranes (GIMs) were developed via interlaced stacking of one-dimensional Gd (III)-imprinted carbon nanotubes (GICNTs) and two-dimensional polydopamine-modified graphene oxide ([email protected]). Polydopamine was synthesized on graphene oxide to large enhance the interfacial adhesion, and ion-imprinting polymerization is implemented on carbon nanotubes (CNTs) by direct cross-link of linear polymers. The obtained materials are characterized in detail by FTIR, SEM, TEM and AFM to explorer the evolution of chemical composition and morphology. Selectivity towards Gd (III) is obtained by isothermal adsorption, kinetic adsorption and time-depended permeation. Isothermal and kinetic models are fitted with adsorption data to obtain the mechanism of selective separation on GIMs. The as-synthesized GIMs with high permeation selectivity (2.91 and 2.49) towards Gd (III) and stable permeation regeneration would potentially be applied to separation and purification of specific ions form multiple REEs.