South China University of Technology, School of Environment and Energy, Guangzhou, China.
South China University of Technology, School of Environment and Energy, Guangzhou, China; Guangdong Plant Fiber High-Valued Cleaning Utilization Engineering Technology Research Center, Guangzhou, China.
J Hazard Mater. 2021 Jun 5;411:125194. doi: 10.1016/j.jhazmat.2021.125194. Epub 2021 Jan 21.
The poor water stability of metal-organic frameworks (MOFs) significantly hindered their catalytic application in advanced oxidation system. A protective outer layer was an effective strategy to solve this problem. However, the commonly used coating techniques are too complicated or too difficult to accurately control, thus, the applicability was relatively low. In this study, a water stable MOF core-SiO shell nanomaterial (Fe-MOF-74@SiO) was synthesized by a facile hydrothermal method, and applied to activate persulfate (PS) for dimethyl phthalate (DMP) degradation. The catalyst water stability and DMP degradation in the system were investigated, suggesting that the SiO-coated catalyst was more stable and exhibited higher DMP degradation efficiency over the pure MOF. It was found that pH had negligible effects on Fe-MOF-74@SiO + PS system, while, higher temperature facilitated the degradation of DMP. The activation mechanism was studied by quenching experiments combined with electron paramagnetic resonance, indicating that SO played a major role in the activation of PS with Fe-MOF-74@SiO for DMP removal, while OH also involved in the catalytic process. Finally, possible DMP degradation pathways were proposed. These findings indicated that the core-shell structured Fe-MOF-74@SiO showed promise for DMP degradation by PS advanced oxidation system.
金属-有机骨架（MOFs）的较差的水稳定性极大地阻碍了它们在高级氧化系统中的催化应用。保护层是解决此问题的有效策略。然而，常用的涂层技术过于复杂或难以精确控制，因此适用性相对较低。在这项研究中，通过简便的水热法合成了一种水稳定的 MOF 核-SiO 壳纳米材料（Fe-MOF-74@SiO），并将其用于激活过硫酸盐（PS）以降解邻苯二甲酸二甲酯（DMP）。考察了催化剂在该体系中的水稳定性和 DMP 降解性能，表明 SiO 涂层催化剂比纯 MOF 更稳定，且具有更高的 DMP 降解效率。研究发现，pH 值对 Fe-MOF-74@SiO + PS 体系几乎没有影响，而较高的温度有利于 DMP 的降解。通过淬灭实验结合电子顺磁共振研究了其活化机制，表明 SO 在 Fe-MOF-74@SiO 活化 PS 去除 DMP 中起主要作用，而 OH 也参与了催化过程。最后，提出了可能的 DMP 降解途径。这些发现表明，核壳结构的 Fe-MOF-74@SiO 有望通过 PS 高级氧化系统降解 DMP。
