A novel porous SnS nanoflower/graphene oxide composite electrodes for the selective and efficient recovery of ReO4-/TcO4-in harsh environments

99Tc is present in the radioactive wastewater generated from spent fuel reprocessing and poses a serious threat to the environment. Due to the strong radioactivity, high ionic strength, and high acidity of nuclear wastewater, selectively extracting 99Tc remains a significant challenge. This study developed a novel electrochemically switched ion exchange technology and a SnS nanoflower/graphene oxide (SSF/GO) composite electrode for selectively extracting ReO4-/TcO4-. The electrode exhibited a high adsorption capacity of 1812 mg g-1 for Re, and it maintained excellent extraction efficiency even in a high-concentration nitric acid system (3 mol L-1) similar to nuclear wastewater. The SSF/GO electrode also exhibits excellent selectivity and cycling stability. Furthermore, the study revealed that the exceptional performance of the SSF/GO electrode originates from the synergistic effects of electrochemical reduction, chemical reduction, and ion exchange. In conclusion, this research provides valuable insights into the development of efficient synergistic systems integrating electrochemical reduction, chemical reduction, and ion exchange to enhance ion capture efficiency. It holds promising potential for nuclear wastewater treatment by significantly improving ion capture efficiency.