3D carbon aerogels for sustainable solid-phase adsorption of neodymium

Rare earth elements (REEs) are critical materials widely used in electronics, magnets, and clean energy technologies. Nd is among the most economically critical REEs and is a core element of NdFeB magnets used in wind turbines, electric vehicles, and data storage; global demand is projected to reach ~8000 tons by 2030. To address increasing demand, efficient and sustainable recovery of Neodymium (Nd) from spent NdFeB magnets has become an urgent priority. However, conventional REE extraction methods are hindered by limited selectivity, complex operation procedures, high organic solvent usage, or intensive energy consumption. In this study, a novel three-dimensional (3D) graphene oxide aerogel (GOA) functionalized with diglycolamide ligands was fabricated for the first time as a solid-phase adsorbent for Nd extraction. The synthesized diglycolamide-functionalized GOA (D-GOA) composite combines the high surface area and abundant active sites of GOA with the strong REE chelation ability of diglycolamide, offering enhanced affinity and selectivity for trivalent Neodymium ions (Nd 3+ ). The batch adsorption experiments demonstrated that D-GOA achieved a maximum adsorption capacity of 176.26 mg/g for Nd 3+ under optimal conditions, which is superior than most other solid adsorbents for Nd 3+ . After five adsorption–desorption cycles, D-GOA retained over 86 % of its initial capacity, demonstrating excellent reusability. Moreover, in the breakthrough curves, Nd 3+ does not reach saturation until about 27 bed volumes, far beyond Fe 3+ at about 12 bed volumes; in a flow through column treating simulated spent NdFeB leachate, this disparity demonstrates the remarkable selectivity of D-GOA for REEs, attributed to the strong coordination between the diglycolamide ligands and Nd 3+ ions. This study provides a practical and sustainable route for selective Nd recovery and scale up. • A 3D diglycolamide-functionalized GO aerogel (D-GOA) was synthesized by conjugation of REE-specific ligands • Explored the optimal mobile-phase flow rate for D-GOA via breakthrough curves in column-based adsorption. • D-GOA showed excellent selectivity for Nd 3+ over Fe 3+ in column-based adsorption. • D-GOA retained >86 % REE capacity after five reuse cycles, indicating great durability