Yang Pengfei, Shu Yufang, Zhuang Qixin, Li Yongsheng, Gu Jinlou
Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering , East China University of Science and Technology , Shanghai 200237 , China.
Langmuir. 2019 Dec 10;35(49):16226-16233. doi: 10.1021/acs.langmuir.9b03057. Epub 2019 Nov 20.
Highly efficient removal of toxic Cr(VI) from aqueous media remains a crucial concern for ecosystem protection and public health. Herein, we demonstrated a new approach to solve this issue by constructing alkyl thiol-containing Zr-based metal-organic framework (MOF) adsorbents using simple and inexpensive mercaptosuccinic acid (MSA) and -dimercaptosuccinic acid (DMSA) as ligands. These chemically stable MOFs could be prepared in an uncomplicated, green, cost-effective, and scalable way. The interaction mechanism between alkyl thiol groups in MOFs and Cr(VI) was investigated in detail. Thanks to the formation of a Cr(VI)-thiolate complex and the oxidation of thiol groups, these designed MOFs not only exhibited high Cr(VI) adsorption capacities (202.0 and 138.7 mg/g for Zr-MSA and Zr-DMSA, respectively) but also displayed the immobilization ability for concomitant resultant Cr(III). Even in the presence of high concentrations of possibly coexistent interfering ions, the thiol-containing MOFs can still work effectively to decontaminate the Cr(VI) species. In addition, the strategy of introducing thiol groups into MOFs for Cr(VI) reduction and concomitant Cr(III) immobilization is universal for other MOFs, as verified by thiol-containing UiO-66 and MOF-808 prepared by a one-pot method. Therefore, our work not only produces several effective Cr(VI) adsorbents but also sets a general guideline for the construction of Cr(VI) adsorbents by introducing thiol groups into porous materials.
从水介质中高效去除有毒的六价铬仍然是生态系统保护和公众健康的关键问题。在此，我们展示了一种新方法来解决这个问题，即使用简单且廉价的巯基琥珀酸（MSA）和二巯基琥珀酸（DMSA）作为配体，构建含烷基硫醇的锆基金属有机框架（MOF）吸附剂。这些化学性质稳定的MOF可以通过简单、绿色、经济高效且可扩展的方式制备。详细研究了MOF中烷基硫醇基团与六价铬之间的相互作用机制。由于形成了六价铬 - 硫醇盐配合物以及硫醇基团的氧化，这些设计的MOF不仅表现出高的六价铬吸附容量（Zr - MSA和Zr - DMSA对六价铬的吸附容量分别为202.0和138.7 mg/g），而且还显示出对伴随产生的三价铬的固定能力。即使在存在高浓度可能共存的干扰离子的情况下，含硫醇的MOF仍然可以有效地去除六价铬物种。此外，通过一锅法制备的含硫醇的UiO - 66和MOF - 808验证了将硫醇基团引入MOF以还原六价铬并同时固定三价铬的策略对其他MOF是通用的。因此，我们的工作不仅制备了几种有效的六价铬吸附剂，而且还为通过将硫醇基团引入多孔材料来构建六价铬吸附剂设定了一般指导原则。
