Mechanistic insights into heavy metals affinity in magnetic MnO2@Fe3O4/poly(m-phenylenediamine) core - shell adsorbent
Mechanistic insights into heavy metals affinity in magnetic MnO2@Fe3O4/poly(m-phenylenediamine) core - shell adsorbent
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磁性MnO2@Fe3O4/聚间苯二胺核壳吸附剂中重金属亲和力的机理研究
DOI：
10.1016/j.ecoenv.2020.110326
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发表时间：
2020
影响因子：
6.8
通讯作者：
Liu Yue
中科院分区：
文献类型：
--
作者：
Xiong Ting;Yuan Xingzhong;Cao Xuyang;Wang Hou;Jiang Longbo;Wu Zhibin;Liu Yue
吸附是一种很有吸引力的修复污水的方法。遗憾的是，表面正电荷、低表面积和复杂的分离过程限制了聚间苯二胺（PmPD）作为重金属吸附剂的可用性。为了克服这些缺点，设计了一种磁性MnO2@Fe3O4/PmPD核壳吸附剂来去除水中的重金属。kmno4与PmPD氧化还原反应生成的mno2壳层增加了表面面积，改变了表面电负性。MnO2@Fe3O4/PmPD可以很容易地从水中分离。对Pb（II）和Cd（II）的最大去除率分别为438.6 mg/g和121.5 mg/g。重金属与MnO2@Fe3O4/PmPD的亲和主要是由于静电吸引、离子交换和配位相互作用。密度泛函理论（DFT）进一步证实了Pb和Cd与O原子成键。计算出的吸附能表明，（111）mno2微面对Pb（II）的吸附亲和力强于Cd（II）。此外，FM150 （150 mg）以20 mL/min的通量单次通过可过滤柱可再生22 L Pb（II）废水。因此，本研究表明，利用MnO2@Fe3O4/PmPD有效去除废水中的重金属具有良好的潜力。
Adsorption represents an attractive mean to remediate polluted water. Unfortunately, the surface positive charges, low surface area and complicated separation procedures inhibit the usability of poly (m-phenylenediamine) (PmPD) as an adsorbent for heavy metal removing. To overcome these drawbacks, a magnetic MnO2@Fe3O4/PmPD core−shell adsorbent was designed to remove heavy metals from water. The MnO2shell, came from the redox reaction between KMnO4and PmPD, increased the surface area and changed the surface electronegativity. MnO2@Fe3O4/PmPD could be easily separated from water. It showed a significant increase in heavy metals removal efficiency, with maximum capacities of 438.6 mg/g for Pb(II) and 121.5 mg/g for Cd(II), respectively. The affinity between heavy metals and MnO2@Fe3O4/PmPD were mainly due to electrostatic attraction, ion exchanges and coordinated interaction. Density functional theory (DFT) calculations further confirmed that Pb and Cd were bonded with O atoms. The calculated adsorption energy indicated that the (111) MnO2facet presented stronger adsorption affinity toward Pb(II) than Cd(II). Additionally, FM150 (150 mg) could regenerate 22 L Pb(II) wastewater upon single passage through the filterable column with a flux of 20 mL/min. Thus, the present work demonstrates the promising potential of using MnO2@Fe3O4/PmPD for efficiently removing heavy metals from wastewater.