Click‐Stabilized Neodymium‐Ion‐Imprinted Resorcinol–Formaldehyde Resin for Selective Nd 3+ Recovery

Neodymium ion‐imprinted polymer (Nd‐IIP) was synthesized by employing the resorcinol‐formaldehyde resin (RF) as a chemically tunable support for the efficient selective recovery of Nd 3+ ions. RF was cyanoethylated to introduce reactive nitrile groups, which were further modified using 3‐(((furan‐2‐ylmethyl)amino)methyl)‐4‐hydroxybenzohydrazide (FUBH) to synthesize RF‐FUB containing phenolic oxygen, secondary amine nitrogen, and furan rings. Nd 3+ ions were coordinated with RF‐FUB via phenolate oxygen and amino nitrogen in the vicinity, followed by Diels–Alder cross‐linking between furan rings of RF‐FUB and maleimide of bis(maleimido) ethane (BMOE) and subsequent template extraction to fabricate a stable recognition site. Synthesis of FUBH, successive chemical modification of the polymer, Nd 3+ coordination, and cross‐linked imprinting network were established by means of FTIR, XPS, solid‐state 13 C NMR, elemental analysis, TGA/DTG, SEM, and BET measurements. Nd‐IIP exhibited more uneven surface texture, larger surface area, and enhanced thermal stability compared with those of NIP. Adsorption exhibited strong dependency on pH, with optimum performance at pH 6. The Langmuir isotherm fitted the equilibrium data very well and estimated a maximum uptake capacity of 321.9 mg g −1 versus 167.2 mg g −1 for NIP, while kinetic data followed the pseudo‐second‐order model. Competitive adsorption and reuse studies confirmed selective, stable, and regenerable Nd 3+ uptake.