Rare-earth single-atom materials: synthesis and applications.

Rare-earth (RE) single-atom materials have emerged as a frontier field in chemistry and materials science owing to the unique electronic structures of RE elements, particularly their partially filled 4f orbitals and large atomic radii. These intrinsic properties enable high coordination numbers, distinct f-d-p orbital hybridization and pronounced spin-orbit coupling, which collectively endow RE single atoms with exceptional catalytic activity, luminescence, stimuli responsiveness and related functionalities. In this review, we provide a comprehensive overview of recent advances in the synthesis, characterization and applications of RE single-atom materials. We also highlight the underlying mechanisms that link the unique structural features of RE single atoms to their functional performance. Finally, we discuss key challenges and future research directions, aiming to promote the rational design and effective utilization of RE elements in advanced chemistry and functional materials.