Ultrafast, High‐Capacity Uranium Harvesting From Seawater via a Hierarchically Porous Polymer Electrode

ABSTRACT Efficient uranium extraction from seawater is a critical challenge in advancing sustainable nuclear energy, given the vast but dilute reserves of uranium in oceans. Here, we report a hierarchically porous polymer electrode engineered for electrochemical uranium harvesting with unprecedented performance. Fabricated via a non‐solvent phase inversion process, the electrode features an interconnected microporous‐mesoporous architecture that enhances uranium uptake and facilitates ion transport, where the amidoxime groups promote selective adsorption of uranyl ions, and they are subsequently electrodeposited as crystalline (UO 2 )O 2 ·2H 2 O under an applied potential. This solution‐processable microporous polymer electrode exhibits an excellent uranium uptake capacity exceeding 4221 mg g −1 without saturation. The electrode maintains strong reusability and seawater tolerance, enabling rapid and continuous uranium harvesting even at ultratrace concentrations. This work provides a transformative platform for electrochemically‐driven, high‐throughput uranium harvesting from marine resources.