A Comprehensive Review of Adsorbents for Rare Earth Separation: Design, Synthesis, Adsorption Performance, and Mechanisms

ABSTRACT Rare earth elements (REEs) play an irreplaceable role in modern technology and industry. However, due to the highly similar physicochemical properties among REEs, their separation remains a significant challenge. Additionally, REEs often exist in low‐concentration solutions, making efficient REE recovery an urgent task. This paper presents a comprehensive review of the latest research advances in adsorbents for REE adsorption from aqueous solutions. It systematically examines the performance characteristics of organic, inorganic, biological, and composite adsorbents, with a focus on innovative design, synthesis strategies, and practical applications of various adsorbents, particularly highlighting their excellent adsorption performance and diverse mechanisms. Notably, composite and hybrid materials significantly enhance adsorption selectivity and stability through synergistic effects. Future research should focus on machine learning (ML)‐driven adsorbent intelligent design using quantitative structure–activity/property relationship (QSAR/QSPR) models, green synthesis pathways, adsorption–desorption performance enhancement, and industrial process optimization via interdisciplinary collaboration. This review aims to provide a systematic reference for research on adsorption and separation of REEs, thereby promoting the development and application of high‐efficiency and eco‐friendly adsorbents.