Radioiodine is highly radioactive and acutely toxic, which can be a serious health threat, and requires effective control. To fully utilize an adsorbent and reduce the overall production cost, successive recycling applications become necessary. Here, 3D formicary-like δ-Bi2O3 (FL-δ-Bi2O3) aerogel adsorbents were synthesized using a one-pot hydrothermal method. In this hybrid structure, abundant flowerlike δ-Bi2O3 (MR-δ-Bi2O3) microspheres were inlaid into the interconnected ant nest channel, forming a 3D hierarchical structure, which is applied as an efficient adsorbent with easy recovery for radioiodine removal. Notably, the FL-δ-Bi2O3 aerogel adsorbent exhibited a very high uptake capacity of 2.04 mmol/g by forming an insoluble Bi4I2O5 phase. Moreover, the FL-δ-Bi2O3 worked in a wide pH range of 4-10 and displayed fast uptake kinetics and excellent selectivity due to the 3D porous interconnected network and larger specific surface area. Importantly, the recycling process is easy, using only tweezers to directly move the 3D aerogel adsorbents from one reaction system to another. Therefore, the FL-δ-Bi2O3 aerogel may be a promising practical adsorbent for the selective capture of radioactive iodide.
Keywords: formicary-like δ-Bi2O3; green chemistry; hybrid 3D structure; selective iodine capture; water purification.