A chitosan-based Y3+-imprinted hydrogel with reversible thermo-responsibility for the recovery of rare earth metal

• A chitosan-based Y 3+ -imprinted hydrogel (CYIT) was prepared for recovery of Y 3+ . • The obtained CYIY possesses stable reversible thermo-responsibility. • The maximum adsorption capacity of CYIT on Y 3+ reaches 160.0 mg/g. • Only cold water leaching is required for the regeneration of CYIT. • CYIT exhibits remarkable reusability and high adsorption selectivity. Recovery of rare earth metal is a global concern for resource-efficient application and high-tech industry development. In this study, a new Y 3+ adsorbent, namely chitosan-based Y 3+ -imprinted hydrogel with reversible thermo-responsibility (CYIT) was synthesized, using Y 3+ as the template ion. The obtained CYIT was comprehensively characterized by means of DSC, FTIR, LRS, TGA, SEM, and XPS. As revealed from the results, CYIT possesses stable reversible thermo-responsibility confirmed by the phase transition temperature ranging from 29.2°C to 38.4°C. Its maximum adsorption capacity on Y 3+ is up to 160.0 mg/g, much higher than the corresponding performance of similar hydrogels. More significantly, this type of adsorbent could be effectively regenerated by simply leaching with cold water and the desorption efficiency reached 96.2% after wash by cold water at 15°C for 25 min. Besides, the remarkable reusability should also be highlighted, for the adsorption capacity and desorption efficiency remained as 124.8 mg/g and 90.0%, respectively, after five adsorption-desorption cycles. In the coexistence of other interfering metal ions (including La 3+ , Gd 3+ , Cu 2+ , Al 3+ , and Fe 3+ ), CYIT also exhibited better adsorption selectivity than the corresponding adsorbent without Y 3+ -imprinting.