Ag-doped silicon-based nanospheres for the efficient capture and remove of iodide anions from solutions

A novel Ag-doped silicon-based nanosphere (MSA) adsorbent is successfully prepared via a layer-by-layer assembly method for efficient capture of radioactive iodide from aqueous solutions. The Ag2O nanoclusters was uniformly embedded into the flexible MPs-SiO2 to construct a heterogeneous silver platform on the surface of silicon-based materials, resulting in massive generation of high specific binding sites, which were regarded as the strong binding center of radioiodine anion. And incorporation of SiO2 into the intermediate layer can improve chemical and thermal stability of MSA and protects the core from corrosion of electrochemical reactions. Predominant MSA adsorbent exhibited an excellent adsorption capacity of I- (236.98 mg/g) which was attributed to the irreversible reaction process of AgI solid-liquid interface precipitation between I- and the Ag2O nanoclusters of interfacial site-directed growth on MPs-SiO2. The MSA adsorbent also exhibited a rapid adsorption process and was consistent with the pseudo-second-order kinetics model. Furthermore, the selectivity of the MSA adsorbent for I- was found to be fairly desirable by the adsorption tests under the harsh conditions. These results indicate that superior MSA can find practical applications in the fields of the radionuclides removal and recovery.