Single-step annealed Ti9O17/Ti electrode for electrochemical separation and recovery of uranium from organic-containing uranium wastewater

The efficient removal of uranium from organic-containing uranium wastewater (OCUW) presents significant technical challenges. Titanium dioxide (TiO 2 ) demonstrates high activity toward uranium reduction, rendering it an excellent electrode candidate for direct electrochemical reduction to remove uranium from such wastewater. In this study, a novel titanium dioxide electrode was fabricated via a facile one-step annealing method for highly efficient uranium electro-separation and recovery from OCUW. The Ti 9 O 17 /Ti electrode exhibited remarkable uranium removal performance across a wide pH range (3−11) and uranium concentration range (10–500 ppm), achieving a removal efficiency of over 93 % within 5 h. Moreover, it demonstrated strong anti-interference capability against coexisting organic matters, except for NH 4 NO 3 , achieving a uranium removal efficiency of 99.89 % within 3 h even in authentic complex OCUW containing high concentrations of THFA, PVA, urea, and NH 4 NO 3 . Notably, the electrode retained a uranium removal efficiency exceeding 90 % after 15 consecutive separation-recovery cycles, and over 85 % of the uranium could be rapidly recovered using dilute nitric acid. Mechanistic studies revealed that uranyl reduction follows a diffusion-controlled single-electron transfer mechanism, and the mechanistic process of electro-separation was elucidated. This work demonstrates that the Ti 9 O 17 /Ti electrode-based electro-separation represents a robust strategy for treating complex uranium-containing wastewater with coexisting organics, offering significant implications for environmental protection and sustainable uranium resource utilization.