Removal of radioactive iodine from water using Ag2O grafted titanate nanolamina as efficient adsorbent

Highlights: ► Ag2O nanocrystals were deposited on titanate nanolamina prepared from TiOSO4. ► The composite is efficient adsorbent for removal of radioactive Iodine from water. ► The adsorbent exhibited a high capacity of 3.4 mmol of iodine per gram of adsorbent in 1 h. ► Ag2O nanocrystals are firmly anchored on the surface of the titanate lamina by coherent interface. ► The adsorbent can be recovered easily for safe disposal and suitable for column adsorption-bed. -- Abstract: Emergency treatment of radioactive material leakage and safety disposal of nuclear waste is a constant concern all along with the development of radioactive materials applications. To provide a solution, titanate with large surface area (143 m2 g−1) and a lamina morphology (the thickness of the lamina is in range of tens of nanometers) was prepared from inorganic titanium compounds by hydrothermal reactions at 433 K. Ag2O nanocrystals (5–30 nm) were deposited onto the titanate lamina. The surface of the titanate lamina has crystallographic similarity to that of Ag2O nanocrystals. Hence, the deposited Ag2O nanocrystals and titanate substrate join together at these surfaces, forming a well-matched phase coherent interface between them. Such coherence between the two phases reduces the overall energy by minimizing surface energy and anchors the Ag2O nanocrystals firmly on the external surface of the titanate structure. The composite thus obtained was applied as efficient adsorbent to remove radioactive iodine from water (one gram adsorbent can capture up to 3.4 mmol of I− anions). The composite adsorbent can be recovered easily for safe disposal. The structure changes of the titanate lamina and the composite adsorbent were monitored by various techniques. The isotherm and kinetics of iodine adsorption, competitive adsorption and column adsorption using the adsorbent were studied to assess its iodine removal abilities. The adsorbent exhibited a capacity as high as 3.4 mmol of iodine per gram of adsorbent in 1 h. Therefore, Ag2O deposited titanate lamina is an effective adsorbent for removing radioactive iodine from water