Wang Xingyue, Ma Yuhan, Jiang Jingjing, Li Mingyu, Li Tianren, Li Chaoqun, Dong Shuangshi
Key Laboratory of Groundwater Resources and Environment (Jilin University), Ministry of Education, Jilin University, Changchun 130021, Jilin, China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Jilin University, Changchun 130021, Jilin, China.
Key Laboratory of Groundwater Resources and Environment (Jilin University), Ministry of Education, Jilin University, Changchun 130021, Jilin, China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Jilin University, Changchun 130021, Jilin, China.
J Hazard Mater. 2022 Jul 15;434:128864. doi: 10.1016/j.jhazmat.2022.128864. Epub 2022 Apr 18.
MIL-53(Fe) catalyst has been widely used to treat the pollutants in water. However, the limited number of electrons in MIL-53(Fe) catalyst has always affected the rate at which Fe can be reduced to Fe. We modulated iron-based metal-organic frameworks (MOFs) using organic ligands modified with chlorine functional groups. The characterization results indicate that the 2Cl-MIL-53(Fe) catalyst exhibited the optimal photoelectric properties while maintaining the original structural characteristics. The experimental analyses and the first-principles study suggest that the introduction of a chlorine functional group not only reduced the band gap width and enhanced the visible-light absorption capacity, but also significantly enhanced the electron cloud density of Fe-O clusters. This could further accelerate the redox cycle of Fe(III)/Fe(II), beneficial for HO activation. The constructed Cl-MIL-53(Fe) catalyst exhibited a 3.8 times higher reaction rate constant than pure MIL-53(Fe) catalyst. The specific TCH degradation pathway and mechanism of 2Cl-MIL-53(Fe) treatment are proposed. This study provides a new strategy for iron-based MOFs as a heterogeneous photo-Fenton catalyst to degrade pollutants in water.
MIL-53(Fe)催化剂已被广泛用于处理水中的污染物。然而，MIL-53(Fe)催化剂中有限的电子数量一直影响着Fe还原为Fe²⁺的速率。我们使用经氯官能团修饰的有机配体对铁基金属有机框架（MOFs）进行了调制。表征结果表明，2Cl-MIL-53(Fe)催化剂在保持原始结构特征的同时展现出了最佳的光电性能。实验分析和第一性原理研究表明，氯官能团的引入不仅减小了带隙宽度、增强了可见光吸收能力，还显著提高了Fe-O簇的电子云密度。这能够进一步加速Fe(III)/Fe(II)的氧化还原循环，有利于·OH的活化。所构建的Cl-MIL-53(Fe)催化剂的反应速率常数比纯MIL-53(Fe)催化剂高3.8倍。提出了2Cl-MIL-53(Fe)处理TCH的具体降解途径和机制。本研究为铁基MOFs作为非均相光芬顿催化剂降解水中污染物提供了一种新策略。
