Atomically precise Au25(SR)18 (SR: thiol ligand) nanoclusters with adjustable charge states (−1, 0, +1) provide an ideal platform to explore the chemical properties of charged active sites and reveal the structure-ability relationship at a single-electron level. Owing to the different affinity of charged active sites towards specific reactants, it inspires us to investigate the adsorption ability of Au25q nanoclusters (q = −1, 0, +1) towards UO 2 2+ , which are an important raw of nuclear energy. In this work, three Au 25 −1, 0, +1 nanoclusters with similar crystalline structures but different electron configurations are synthesized, and their uranium extraction ability is explored via the electrochemical pulse technique. First, theoretical calculations predict that Au 25 − has a stronger binding ability for UO 2 2+ than Au 25 0 and Au 25 + . Then, the experimental results demonstrate that the Au 25 − nanoclusters display the best removal capacity, with a removal efficiency of >95% in simulated seawater with 1–20 ppm UO2(NO3)2. The extraction capacity of Au 25 − can reach 887.9 mg g−1, and the removal efficiency could be 88% in simulated seawater with 50 ppm UO2(NO3)2. The excellent extraction performance of Au 25 − nanoclusters might be attributed to the enhanced capture of UO 2 2+ through electronic attraction, which could further be effectively electro-reduced under an externally applied potential. This work deeply reveals the structure-ability relationship between metal nanoclusters and uranium extraction performance at a single-electron level, which can provide valuable guidance for developing efficient absorbents.
