Surface Modulation and Chromium Complexation: All-in-One Solution for the Cr(VI) Sequestration with Bifunctional Molecules
Surface Modulation and Chromium Complexation: All-in-One Solution for the Cr(VI) Sequestration with Bifunctional Molecules
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表面调制和铬络合：双功能分子螯合 Cr(VI) 的一体化解决方案
DOI：
10.1021/acs.est.0c00710
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发表时间：
2020
影响因子：
11.4
通讯作者：
Xu Chunhua
中科院分区：
文献类型：
--
作者：
Gao Xuyan;Zhang Yue;Li Fengmin;Tian Boyang;Wang Xiao;Wang Zhiwei;Carozza Jesse C.;Zhou Zheng;Han Haixiang;Xu Chunhua
零价铁（ZVI）硫化成Fe@FeSx（S-ZVI）复合材料已在ZVI领域被深入研究。然而，很少实现FeSx涂层的进一步益处，特别是那些有效地利用其固有的物理和化学性质进行精细设计的益处。在这里，我们证明了在传统的Cr（VI）螯合反应中，FeSx层在固定含有羟基（−OH）的分子方面显示出很大的实用性，因此，吸引了与羧基有机物（RCOOH）螯合的Cr（VI）络合物。这种分子间吸引力容易促进Cr（VI）络合物扩散到S-ZVI表面，从而为Cr（VI）螯合过程提供更高的反应速率。此外，上述机理用于指导以适当比例结合羟基和羧基官能团的分子的合理选择，从而实现显著提高的反应效率。此外，FeSx相被发现在反应中被消耗，作为补充还原剂。这项工作是第一次揭开特定功能化的分子和FeSx相之间的关系，提供了一个一般规则，在选择适当的反应介质的Cr（VI）螯合和相关的反应。
The sulfidation of zero valent iron (ZVI) to an Fe@FeSx(S-ZVI) composite has been intensively explored in the ZVI field. Yet, further benefits from the FeSxcoating layer are seldom realized, especially those effectively using its intrinsic physical and chemical properties for elaborate design. Here, we demonstrate that in a traditional Cr(VI) sequestration reaction, the FeSxlayer displays a great utility in immobilizing molecules containing hydroxyl groups (−OH) and hence, attracting Cr(VI) complexes chelated with carboxyl organics (RCOOH). Such intermolecular attraction readily promotes the diffusion of the Cr(VI) complexes to the S-ZVI surface, affording a higher reaction rate for the Cr(VI) sequestration process. In addition, the above mechanism was used to guide a rational selection of molecules incorporating both hydroxyl and carboxyl functional groups with a proper ratio and thereby, a significantly improved reaction efficiency was achieved. Furthermore, the FeSxphase was revealed to be consumed in the reaction, acting as a supplementary reductant. This work is the first to unveil the relationship between molecules with specific functionalization and the FeSxphase, providing a general rule in choosing appropriate reaction media for Cr(VI) sequestration and related reactions.