Effective electrochemical uranium extraction from aqueous solution using boron-doped diamond films as a sustainable electrode

• Boron-doped diamond as sustainable electrode for electrochemical uranium extraction. • The film electrode exhibits an impressive extraction efficiency of 1.0 mg (U) cm −2 . • The uranium extraction species are evolved into two products, UO 2 and UO 3 ·2H 2 O. • The recovery efficiency is ∼98 %, even after up to 30 extraction-elution cycles. The decontamination and enrichment of uranium from uraniferous aqueous solution is critically important for ensuring environmental safety and promoting the sustainable development of nuclear energy. Electrochemical extraction possesses the capability to accelerate the directed migration of ions and effectively overcome coulombic repulsion, but no satisfactory electrode. Herein, we pioneered a boron-doped diamond (BDD) film electrode with the prolonged operational lifespan and cost-effective profile for electrochemical uranium extraction. As expected, BDD electrode exhibited an impressive uranium extraction efficiency of ∼1.0 mg cm −2 for 11 h at applied voltage spanning from 0 to −2 V (10 mg L −1 U(VI)), even after up to 30 extraction-elution cycles. The extraction mechanism was corroborated by X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy and X-ray absorption spectroscopy, whereby the extraction species was transformed into two products, UO 2 and UO 3 ·2H 2 O. Due to the lack of adsorption effect on uranium species by the BDD electrode, the elution recovery of extraction products deposited via diffusion effect is remarkably straightforward, achieving a recovery rate of approximately ∼98 %. This work not only provides a novel electrode material for electrochemical uranium extraction, but also paves the way for an eye-catching electrochemical extraction strategy for some key radionuclides using the extremely stable doped diamond electrodes.