Molecular recognition and cross scale mechanisms for selective uranium recovery from seawater

Seawater contains a vast reservoir of uranium, but its practical recovery remains challenging because of the extremely low uranyl concentration, strong competition from coexisting ions, and the complexity of the marine environment. Unlike previous reviews organized by material class, this work develops a cross-scale framework that integrates molecular recognition, interfacial selectivity, and transport and failure processes, thereby linking atomic level interactions with engineering relevant performance. Molecular studies supported by computation and in situ spectroscopy reveal the coordination behavior of uranyl ions and competitive binding pathways, enabling transferable design principles such as geometric matching and multidentate cooperativity. Transport analyses under ultradilute conditions highlight the importance of hierarchical porosity, electrostatic pre-enrichment, and rapid ion access for improving adsorption kinetics. Understanding degradation pathways, including biofouling, corrosion, and irreversible binding, further guides the development of stable matrices, antifouling interfaces, efficient elution strategies, and self-healing functionalities. In addition, redox mediated regeneration offers a promising route to improve sorbent reusability. We also provide quantitative comparisons of selectivity mechanisms, real seawater performance, and engineering readiness to facilitate objective assessment across different material platforms. Remaining challenges include reproducing marine complexity in laboratory tests, reducing regeneration energy demand, and demonstrating long term durability under realistic conditions. Overall, this review offers a mechanism driven roadmap for the rational design of durable, scalable, and selective sorbents for uranium recovery from seawater.