Water stable SiO2-coated Fe-MOF-74 for aqueous dimethyl phthalate degradation in PS activated medium

Su Ding; Jinquan Wan; Yongwen Ma; Yan Wang; Mengjie Pu; Xitong Li; Jian Sun

doi:10.1016/j.jhazmat.2021.125194

Water stable SiO₂-coated Fe-MOF-74 for aqueous dimethyl phthalate degradation in PS activated medium

J Hazard Mater. 2021 Jun 5:411:125194. doi: 10.1016/j.jhazmat.2021.125194. Epub 2021 Jan 21.

Authors

Su Ding¹, Jinquan Wan², Yongwen Ma³, Yan Wang³, Mengjie Pu⁴, Xitong Li¹, Jian Sun¹

Affiliations

¹ South China University of Technology, School of Environment and Energy, Guangzhou, China.
² 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. Electronic address: ppjqwan@scut.edu.cn.
³ 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.
⁴ Research Center for Eco-Environmental Engineering, Dongguan University of Technology, Dongguan, China.

PMID: 33858121
DOI: 10.1016/j.jhazmat.2021.125194

Abstract

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-SiO₂ shell nanomaterial (Fe-MOF-74@SiO₂) 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 SiO₂-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@SiO₂ + 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 SO₄^⋅^- played a major role in the activation of PS with Fe-MOF-74@SiO₂ 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@SiO₂ showed promise for DMP degradation by PS advanced oxidation system.

Keywords: Advanced oxidation processes (AOPs); Dimethyl phthalate; Persulfate; SiO(2)-coated Fe-MOF-74; Water stability.

Publication types

Research Support, Non-U.S. Gov't