Defect Control in Zr-Based Metal-Organic Framework Nanoparticles for Arsenic Removal from Water
Defect Control in Zr-Based Metal-Organic Framework Nanoparticles for Arsenic Removal from Water
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DOI：
10.1021/acsanm.0c01696
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发表时间：
2020-09-25
影响因子：
5.9
通讯作者：
Hmadeh, Mohamad
中科院分区：
文献类型：
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作者：
Assaad, Nisrine;Sabeh, Ghewa;Hmadeh, Mohamad
在这项研究中，水稳定的锆-金属-有机框架（MOF）（UIO-66）纳米粒子的各种缺陷浓度的成功制备和检查作为吸附剂从水中去除砷酸盐。诱导的缺陷是由于向合成混合物中加入一元羧酸调节剂[乙酸或三氟乙酸（TFA）]所致。通过改变调制剂的种类和数量，可以有效地调节和控制缺陷的浓度。结果表明，不同的样品对水中的砷酸根具有不同的吸附容量，其中，调制最大的样品通过使用TFA作为调节剂获得的（UiO-66- 36 TFA）在中性pH下显示出约200 mg g（-1）的吸附容量，这不仅在所研究的样品中是最高的，而且据我们所知，通过在UiO-66中引入缺陷，与本研究中测试的无缺陷UiO-66相比，砷酸盐摄取百分比提高了100%以上。上级砷吸收归因于由于缺失的连接体缺陷而在MOF簇中形成的游离刘易斯酸位点。此外，纳米粒子表现出突出的砷酸盐对干扰阴离子的选择性，并有效地回收，以保持相同的吸附容量后，五个再生周期。此外，少量的该样品（0.5 mg）被用于完全去除超痕量砷酸盐（5 ppb），证明了其在实际应用中的高效率。因此，有缺陷的纳米级UiO-66样品为未来的水净化技术铺平了道路。
In this study, water-stable Zr-metal-organic framework (MOF) (UiO-66) nanoparticles of various defect concentrations were successfully prepared and examined as the adsorbent for arsenate removal from water. The induced defects resulted from the addition of a monocarboxylic acid modulator [acetic acid or trifluoroacetic acid (TFA)] to the synthesis mixture. The concentrations of the defects were effectively tuned and controlled by changing the type and the amount of the modulator. As a result, different adsorption capacities for arsenate from water were obtained, in which the most modulated sample (UiO-66-36TFA) which was obtained by using TFA as the modulator showed an adsorption capacity around 200 mg g(-1) at neutral pH that is the highest not only among the studied samples but also, up to our knowledge, among all other reported MOFs at neutral pH. By introducing the defects in UiO-66, the arsenate uptake percentage was enhanced by more than 100% compared to defect-free UiO-66 tested in this study. The superior arsenic uptake is attributed to the free Lewis acid sites formed in the MOF clusters as a result of missing linker defects. In addition, the nanoparticles showed outstanding arsenate selectivity against interfering anions and were efficiently recycled to maintain the same adsorption capacity after five regeneration cycles. Furthermore, a small quantity of this sample (0.5 mg) was employed to completely remove ultratrace arsenate (5 ppb), proving its high efficiency in real-life applications. Accordingly, defected nanoscale UiO-66 samples pave the way for future water purification technologies.