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 δBi₂O₃ (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 CO₃^2-, 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.