Roughly 4 billion tons of uranium exists in the oceans, which equates to a nearly inexhaustible supply for nuclear power production. However, the extraction of uranium from seawater is highly challenging due the background high salinity and uranium's relatively low concentration (∼3 μg L⁻¹). Current approaches are generally limited by either their selectivity, sustainability, or their economic competitiveness. Here we engineered a biomass-derived microporous membrane, based on the interfacial formation of robust metal–phenolic networks (MPNs), for uranium capture from seawater. These membranes displayed advantages in terms of selectivity, kinetics, capacity, and renewability in both laboratory settings and marine field-testing. The MPN-based membranes showed a greater than ninefold higher uranium extraction capacity (27.81 μg) than conventional methods during a long-term cycling extraction of 10 L of natural seawater from the East China Sea. These results, coupled with our techno-economic analysis, demonstrate that MPN-based membranes are promising economically viable and industrially scalable materials for real-world uranium extraction.

Bayberry tannin (BT), a natural plant polyphenol, was used for one-step synthesis of gold nanoparticles (AuNPs) in aqueous solution at room temperature. During the synthetic process, BT simultaneously serves as a reducing agent and stabilizing agent, while no additional reagent (surfactant, template, and capping agent) or treatment (heat and photo-irradiation) is needed. The particle diameter and size distribution of BT-stabilized AuNPs (BT-AuNPs) can be facilely controlled by varying the concentration of BT, and the particle size of BT-AuNPs is as small as 1.8 ± 0.3 nm when the BT concentration was 800 mg L⁻¹. Furthermore, this green approach for the auto-reduction synthesis of AuNPs can be completed in several minutes and exhibits high reproducibility, which shows great potential for practical applications.