Bionic chitosan-carbon imprinted aerogel for high selective recovery of Gd(Ⅲ) from end-of-life rare earth productions

High selective recovery of Gd(Ⅲ) from end-of-life rare earth productions is essential for cleaner production. Chitosan(CS), a biomaterial, has shown excellent results in water treatment. The amino and hydroxyl groups on the surface of CS play a vital role in adsorbing metal ions. Polydopamine has good stability, strong water dispersibility, and excellent biocompatibility. As a bio-crosslinking agent, the amino and phenolic hydroxyl groups on its surface can be combined with metal ions to help the material absorb metal ions. This paper combines the active groups of biomimetic materials and the mechanical properties of new nanomaterials multi-walled carbon nanotubes and graphene oxide, and prepared a high-performance chitosan-based aerogel MWCNT-PDA-CS-GO through heat and mass transfer at low temperature and low pressure. The adsorption mechanism of MWCNT-PDA-CS-GO for Gd(Ⅲ) was analyzed through a series of characterization and adsorption experiments. At pH 7.0, the maximum adsorption capacity of aerogel for Gd(Ⅲ) reached 150.86 mg g-1. The relative selectivity of imprinted ions is 48.02 times higher than other ions. All the results indict MWCNT-PDA-CS-GO aerogel exhibits excellent selectivity and stability for effective recovery of Gd(Ⅲ).