School of Chemistry, Physics, Mechanical Engineering, Queensland University of Technology, GPO Box 2434, Brisbane, QLD 4001, Australia.
J Hazard Mater. 2013 Feb 15;246-247:199-205. doi: 10.1016/j.jhazmat.2012.12.008. Epub 2012 Dec 10.
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 m(2)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. Ag(2)O nanocrystals (5-30 nm) were deposited onto the titanate lamina. The surface of the titanate lamina has crystallographic similarity to that of Ag(2)O nanocrystals. Hence, the deposited Ag(2)O 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 Ag(2)O 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 1h. Therefore, Ag(2)O deposited titanate lamina is an effective adsorbent for removing radioactive iodine from water.
放射性物质泄漏的紧急处理和核废料的安全处置是放射性物质应用不断发展所关注的问题。为了解决这个问题，我们通过在 433 K 下的水热反应，由无机钛化合物制备出具有大表面积（143 m(2)g(-1))和片状形态（片层厚度在几十纳米范围内）的钛酸盐。Ag(2)O 纳米晶体（5-30 nm）沉积在钛酸盐片层上。钛酸盐片层的表面与 Ag(2)O 纳米晶体具有结晶相似性。因此，沉积的 Ag(2)O 纳米晶体和钛酸盐基底在这些表面上结合在一起，在它们之间形成了一个良好匹配的、具有相位相干性的界面。这种两相之间的相干性通过最小化表面能来降低总能量，并将 Ag(2)O 纳米晶体牢固地固定在钛酸盐结构的外表面上。将得到的复合材料用作从水中去除放射性碘的高效吸附剂（一克吸附剂可以捕获高达 3.4 mmol 的 I(-)阴离子）。可以方便地回收复合材料吸附剂，进行安全处置。通过各种技术监测了钛酸盐片层和复合吸附剂的结构变化。研究了碘吸附的等温线和动力学、竞争吸附和使用吸附剂的柱吸附，以评估其去除碘的能力。吸附剂在 1 h 内表现出高达每克吸附剂 3.4 mmol 的碘的容量。因此，Ag(2)O 沉积的钛酸盐片层是一种从水中去除放射性碘的有效吸附剂。
