Venkata Sravani V, Tripathi Sarita, Sreenivasulu B, Kumar Satendra, Maji S, Brahmmananda Rao C V S, Suresh A, Sivaraman N
Homi Bhabha National Institute, Indira Gandhi Centre for Atomic Research Kalpakkam 603102 Tamil Nadu India.
Material Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research Kalpakkam-603 102 Tamil Nadu India
RSC Adv. 2021 Aug 19;11(45):28126-28137. doi: 10.1039/d1ra02971a. eCollection 2021 Aug 16.
A simple and efficient route to develop various novel functionalized MOF materials for rapid and excellent recovery of U(vi) from aqueous medium, along with selective sensing has been demonstrated in the present study. In this connection, a set of four distinct post synthetically modified (PSM) iso-reticular metal organic frameworks were synthesized from IRMOF-3 namely, IRMOF-PC (2-pyridine carboxaldehyde), IRMOF-GA (glutaric anhydride), IRMOF-SMA (sulfamic acid), and IRMOF-DPC (diphenylphosphonic chloride) for the recovery and sensing of U(vi) from aqueous medium. The MOFs were characterized by Fourier transform infrared spectroscopy (FTIR), powder XRD, BET surface area analysis, thermogravimetric analysis (TGA), NMR (C, H and P), Scanning Electron Microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). Among all MOFs, post synthetically modified IRMOF-SMA showed enhanced thermal stability of about 420 °C. The MOFs were investigated for U(vi) sorption studies using a batch technique. All the MOFs exhibit excellent sorption capacity towards U(vi) (>90%) and maximum uptake was observed at pH 6. Sorption capacity of MOFs have the following order; IRMOF-3-DPC (300 mg U g) > IRMOF-SMA (292 mg U g) > IRMOF-PC (289 mg U g) > IRMOF-GA (280 mg U g) > IRMOF-3 (273 mg U g). IRMOF-DPC shows rapid sorption of uranium within 5 min with excellent uptake of U(vi) (>99%). The desorption of U(vi) was examined with different eluents and 0.01 M HNO was found to be most effective. The fluorescence sensing studies of U(vi) IRMOF-3 and its PSM MOFs revealed high sensitivity and selectivity towards U(vi) over other competing rare earth metal ions (La, Ce, Sm, Nd, Gd, and Eu), wherein IRMOF-GA displayed an impressive detection limit of 0.36 mg L for U(vi).
本研究展示了一条简单有效的途径,可用于开发各种新型功能化金属有机框架材料,以便从水介质中快速且高效地回收U(vi),同时还具备选择性传感功能。在此方面,通过IRMOF-3合成了一组四种不同的后合成修饰(PSM)同构网状金属有机框架,即用于从水介质中回收和传感U(vi)的IRMOF-PC(2-吡啶甲醛)、IRMOF-GA(戊二酸酐)、IRMOF-SMA(氨基磺酸)和IRMOF-DPC(二苯基膦酰氯)。这些金属有机框架通过傅里叶变换红外光谱(FTIR)、粉末XRD、BET表面积分析、热重分析(TGA)、核磁共振(C、H和P)、扫描电子显微镜(SEM)以及能量色散X射线光谱(EDX)进行了表征。在所有金属有机框架中,后合成修饰的IRMOF-SMA显示出约420℃的增强热稳定性。使用分批技术对这些金属有机框架进行了U(vi)吸附研究。所有金属有机框架对U(vi)均表现出优异的吸附能力(>90%),且在pH为6时观察到最大吸附量。金属有机框架的吸附能力顺序如下:IRMOF-3-DPC(300 mg U/g)>IRMOF-SMA(292 mg U/g)>IRMOF-PC(289 mg U/g)>IRMOF-GA(280 mg U/g)>IRMOF-3(273 mg U/g)。IRMOF-DPC在5分钟内显示出对铀的快速吸附,对U(vi)的吸附效果极佳(>99%)。用不同洗脱剂对U(vi) 的解吸进行了研究,发现0.01 M HNO最为有效。对U(vi)、IRMOF-3及其PSM金属有机框架的荧光传感研究表明,其对U(vi) 相对于其他竞争性稀土金属离子(La、Ce、Sm、Nd、Gd和Eu)具有高灵敏度和选择性,其中IRMOF-GA对U(vi) 显示出令人印象深刻的0.36 mg/L检测限。