Selective Capture of Iodide from Solutions by Microrosette-like δ-Bi2O3

Radioactive iodine isotopes that are produced in nuclear power plants and used in medical research institutes could be a serious threat to the health of many people if accidentally released to the environment because the thyroid gland can absorb and concentrate them from a liquid. For this reason, uptake of iodide anions was investigated on microrosette-like δ-Bi2O3 (MR-δ-Bi2O3). The MR-δ-Bi2O3 adsorbent showed a very high uptake capacity of 1.44 mmol g–1 by forming insoluble Bi4I2O5 phase. The MR-δ-Bi2O3 also displayed fast uptake kinetics and could be easily separated from a liquid after use because of its novel morphology. In addition, the adsorbent showed excellent selectivity for I– anions in the presence of large concentrations of competitive anions such as Cl– and CO32–, and could work in a wide pH range of 4–11. This study led to a new and highly efficient Bi-based adsorbent for iodide capture from solutions.