Rapid Reconstruction of Commercial Bulk Niobium Oxide for Highly Stable Electrochemical Uranium Extraction in the Presence of Fluorine
Electrochemical uranium extraction from fluorine-containing nuclear wastewater is critical for nuclear fuel recovery, yet current electrode materials suffer from limited scalability and insufficient long-term stability. Here, we report a bulk monoclinic Nb2O5−x (H-Nb2O5−x) derived from commercial bulk niobium oxide via rapid reconstruction, exhibiting exceptional activity and robustness for electrochemical uranium extraction in fluorine-rich environments. The intrinsic active pairs of low-valent Nb4+ and compact oxygen structure strongly bind with dominant uranyl fluoride species (UO2F+, UO2F2, UO2F3−, UO2F4^2−), facilitating efficient separation. In a 30 g L−1 fluoride solution, H-Nb2O5−x achieved a uranium extraction efficiency of 99.1%. Notably, in a 10-L real nuclear wastewater test, the bulk material maintained stable performance over 40 days, reducing uranium concentration from 1372.3 mg L−1 to 0.93 mg L−1. This work demonstrates a scalable, durable electrode material for industrial electrochemical uranium extraction, addressing the bottlenecks of complexation and stability in fluoride-containing waste streams.