Safe disposal of radioactive iodide ions from solutions by Ag2O grafted sodium niobate nanofibers

Abstract

Radioactive iodine isotopes are released into the environment by the nuclear industry and medical research institutions using radioactive materials, and have negative effects on organisms living within the ecosystem. Thus, safe disposal of radioactive iodine is necessary and crucial. For this reason, the uptake of iodide ions was investigated in Ag₂O nanocrystal grafted sodium niobate nanofibers, which were prepared by forming a well-matched phase coherent interface between them. The resulting composite was applied as an efficient adsorbent for I⁻ anions by forming an AgI precipitate, which also remained firmly attached to the substrates. Due to their one-dimensional morphology, the new adsorbents can be easily dispersed in liquids and readily separated after purification. This significantly enhances the adsorption efficiency and reduces the separation costs. The change in structure from the pristine sodium niobate to Ag₂O anchored sodium niobate and to the used adsorbent was examined by using various characterization techniques. The effects of Ag⁺ concentration, pH, equilibration time, ionic strength and competing ions on the iodide ion removal ability of the composite were studied. The Ag₂O nanocrystal grafted sodium niobate adsorbent showed a high adsorption capacity and excellent selectivity for I⁻ anions in basic solutions. Our results are useful for the further development of improved adsorbents for removing I⁻ anions from basic wastewater.