Photoelectrochemical in situ oxygen generation and medium synergy for efficient single-step Yb/Lu separation

In order to obtain 177 Lu with both diagnostic and therapeutic functions from the preparation process of carrier-free 177 Lu, the separation of 176 Yb/ 177 Lu is required. However, the existing electrochemical methods require high voltage, are not conducive to controlling the pH value of the system, and need to be carried out under anaerobic conditions. Herein, this study innovatively proposes to synergize the combination of photocatalysis and electrochemistry, the bridging role of the medium, and the electron transfer effect of oxygen to address the issues existing in the pure electrochemical removal of Yb 3+ . Therefore, using a nitrogen-doped CdS/carbon felt (N-CdS-CF) photoanode, a mercury cathode, and tartaric acid as a medium. Under optimal conditions (initial pH 7.00, 80.0 mg N-CdS-CF, 80 ppm Yb 3+ ), a 40-min treatment at only 6.0 V achieved a 96.7% removal of Yb 3+ —significantly higher than the 42.2% obtained with pure electrochemistry at 8.0 V. Moreover, the pH value of the system is increased and effectively controlled. Meanwhile, the study finds that O₂ in this system not only plays a role in electron transfer to improve the removal of Yb 3+ but also reduces the voltage for water oxidation, thus reducing the generation of H + in the solution. The interaction between tartaric acid, Yb 3+ and mercury helps Yb 3+ to be reduced to form an amalgam. This study has opened up a brand-new technical approach for the efficient and green preparation of carrier-free 177 Lu.