稳定型UiO-66-(COOH)_(2)对Cs^(+)的有效吸附  

Efficient adsorption of Cs^(+)using the stable UiO-66-(COOH)_(2)

作　　者：高源 于睿 周子涵 高禹 蒋荣立[1] GAO Yuan;YU Rui;ZHOU Zihan;GAO Yu;JIANG Rongli(School of Chemical Engineering and Technology,China University of Mining&Technology,Xuzhou 221116)

机构地区：[1]中国矿业大学化工学院,徐州221116

出　　处：《环境科学学报》2023年第6期356-365,共10页Acta Scientiae Circumstantiae

基　　金：江苏省“双创博士”项目(No.2020(31045))。

摘　　要：采用水浴法合成了具有孔道结构、高稳定性和多活性位点的固体吸附材料UiO-66-(COOH)_(2).通过考察接触时间、温度、起始浓度、干扰离子等因素,评估了UiO-66-(COOH)_(2)对放射性铯离子(Cs^(+))的吸附性能.试验表明,吸附过程遵循二级动力学和Langmuir吸附等温线模型,在313 K条件下,最佳吸附容量和去除率分别达到90 mg·g^(-1)和60%.结构表征验证了吸附过程是在Cs^(+)与有机连接体中羧酸根的质子交换以及与金属节点的离子交换的共同作用下进行的.值得注意的是,材料吸附Cs^(+)后仍能保持其化学和热稳定性;同时,在钠和钾干扰离子共存时,UiO-66-(COOH)_(2)对Cs^(+)仍表现出较高的选择性(SCs/M=5)和去除效率(58%).本文的研究结果可为用于核废水处理、放射性污染和放射性同位素回收的新型材料的设计提供重要参考与借鉴.A water bath synthetic strategy was used to produce the adsorbent UiO-66-(COOH)_(2),featuring high stability,large surface area and abundant active sites.Herein,the adsorption properties towards Cs^(+)were evaluated by investigating the significant factors,including concentration,contact time,temperature and selectivity.The batch experiments and kinetic analysis demonstrate that the optimal adsorption capacity reaches 90 mg·g^(-1) with the removal efficiency of 60%at 313 K in aqueous,following a Pseudo-second-order kinetic and Langmuir isotherm model.Furthermore,the mechanism investigations confirm that the Cs^(+)interactions with carboxyl groups in organic linkers and the transmetalation with the metal node of the framework are integrated in the adsorption process.Remarkably,this MOF maintains its chemical and thermal stability after Cs^(+)adsorption.When coexistence with sodium and potassium ions,UiO-66-(COOH)_(2)displays the selectivity towards Cs^(+),with a selectivity coefficient(SCs/M)of 5 and a removal efficiency of 58%.These findings open opportunities for the practical treatment of nuclear waste as well as recycling of radioactive substances.

关 键 词：铯离子(Cs^(+)) 金属有机骨架材料 吸附 选择性 稳定性 吸附机理 

分 类 号：O615.11[理学—无机化学] X703[理学—化学]