硫基层状材料制备及其碘吸附性能研究  

Synthesis and iodine adsorption property of sulfide-based layered material

作　　者：刘意涵 黄莉婷 赵佳慧 张驰 LIU Yihan;HUANG Liting;ZHAO Jiahui;ZHANG Chi(College of Chemistry and Chemical Engineering,Hubei University,Wuhan 430062,China)

机构地区：[1]湖北大学化学化工学院,湖北武汉430062

出　　处：《湖北大学学报（自然科学版）》2024年第4期478-485,共8页Journal of Hubei University：Natural Science

基　　金：有机功能分子合成与应用教育部重点实验室开放基金(KLSAOFM1911)资助。

摘　　要：放射性核废料污染物的处理是核能利用的一项重要研究内容。其中^(129)I因其易扩散和超长半衰期的特点,是危害最为广泛的放射性核素之一。因此,实现放射性碘的富集、储存、循环利用具有重要的意义。近年来,具有丰富软碱配体、灵活多变结构的金属硫属化物被广泛地用于环境废水中重金属离子的富集与回收。这些研究为高效碘捕获剂的开发提供了新方向。根据“软硬酸碱理论”可以预测该类材料对Lewis软酸I_(2)也应具有良好的亲和性。我们在前期研究中制备系列具有层状结构的多元硫化物晶态材料。虽然这些化合物均表现出一定的碘吸附能力,但是性能仍有待提升。为此,本研究通过离子交换法制备金属硫化物团簇[Ge_(4)S_(10)]^(4-)插层的层状双氢氧化物MgAl-[Ge_(4)S_(10)]-LDH。一方面,[Ge_(4)S_(10)]^(4-)团簇的S^(2-)软碱位点充分暴露,不仅增强了其与I_(2)之间的亲和力,还可在吸附过程中将I_(2)还原为I_(3)^(-);另一方面,MgAl-LDH可以提供大量的、有序的阳离子位点,从而提高对碘的吸附保有率。本研究表明,得益于碘与硫基层状材料之间的亲和力及电子转移过程,该吸附剂对碘蒸气的静态吸附容量可达2.52 g/g;对环己烷溶液中的碘同样具有非常高的吸附容量,可达819.67 mg/g。The treatment and disposal of radioactive nuclear waste pollutants is an important research content to realize the utilization of nuclear energy.And radioactive iodine isotopes are one kind of the hazardous radionuclides.Therefore,it is of great significance to achieve the enrichment,storage and recycling of radioactive iodine.In recent years,thiometalates have attracted much attention because of their varied composition,interesting structure,and highly polarized anionic framework.Substantial work has shown that thiometalates possess great potential in effective capture of heavy metal ions.On the basis of the hard soft acid base(HSAB)principle,it has been predicted that chalcogenides might also show good affinity toward I_(2) since iodine is a soft Lewis acid.We previously prepared a series of multinary thiometalates with layered structures.Although all of these crystalline compounds exhibit a certain iodine adsorption capacity,the performance still needs to be improved.Therefore,metal chalcogenide clusters[Ge_(4)S_(10)]^(4-)were inserted into the layered double hydroxide MgAl-LDH by ion-exchange method.On the one hand,the S 2-soft base site of the[Ge_(4)S_(10)]^(4-)cluster was sufficiently exposed,which not only enhanced the affinity with I_(2),but also reduced I_(2) to I_(3)-during the adsorption;on the other hand,the MgAl-LDH could provide a large number of well-ordered cationic sites,thus improving the adsorption retention of iodine.The results indicate that the interactions between iodine and sorbents extend beyond soft Lewis acid-base chemistry into charge transfer process,which is responsible for the large loading static adsorption capacity of 2.52 g/g for I_(2) vapor and 819.67 mg/g for I_(2)-cyclohexane.

关 键 词：硫化物 层状材料 吸附 碘 

分 类 号：TQ424[化学工程] X591[环境科学与工程—环境工程]