Li Dongmei, Hua Tao, Li Xiaoman, Cheng Jianhua, Du Kesi, Hu Yongyou, Chen Yuancai
Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, College of Environment and Energy, South China University of Technology, Guangzhou, 510006, China.
Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, College of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; South China Institute of Collaborative Innovation, Dongguan, 523808, China.
Chemosphere. 2022 Apr;292:133461. doi: 10.1016/j.chemosphere.2021.133461. Epub 2021 Dec 30.
Metal-organic framework (MOFs)-based composites have been popular in photocatalysis due to their outstanding physicochemical properties, such as large surface area, high activity and good transmission properties. Herein, a method of ionic liquids (ILs)-assisted synthesis of IL/MIL-68(In)-NH composite materials were proposed, and composites were used for visible light catalytic degradation of doxycycline hydrochloride (DOXH). The effects of four kinds of ionic liquids on the structure and photocatalytic properties of the composites were explored, including diethylenetriamine acetate ([DETA][OAc]), diethylenetriamine hexafluorophosphate ([DETA][PF]), 1-ethyl-3-methylimidazole acetate ([EMIM][OAc]) and 1-ethyl-3-methylimidazole hexafluorophosphate ([EMIM][PF]). The results show that the introduction of different ionic liquids affects the grain growth of MOFs material and photocatalytic activity. Among them, IL/MIL-68(In)-NH samples showed the highest photocatalytic activity. 92% removal rate of doxycycline hydrochloride and kinetic degradation constant (0.00918 min) was observed under the optimal addition of IL (10 wt%), which was 4.6 times that of MIL-68(In)-NH. The enhancement was attributed to a combined effect of efficient adsorption at low concentration, an increase of active sites, and efficient charge transfer. In addition, the effects of pH and initial concentration were investigated. Finally, the photocatalytic mechanism of DOXH was elucidated, and the possible intermediate products and degradation pathways were discussed. Considering the excellent photostability and ultra-fast photodegradation of IL/MIL-68(In)-NH, this study opens up a new prospect for the preparation of ionic liquids functionalized MOFs with wide practical application value.
基于金属有机框架（MOFs）的复合材料因其优异的物理化学性质，如大比表面积、高活性和良好的传输性能，在光催化领域备受关注。本文提出了一种离子液体（ILs）辅助合成IL/MIL-68（In）-NH复合材料的方法，并将该复合材料用于可见光催化降解盐酸多西环素（DOXH）。研究了四种离子液体，即二乙烯三胺乙酸盐（[DETA][OAc]）、二乙烯三胺六氟磷酸盐（[DETA][PF]）、1-乙基-3-甲基咪唑乙酸盐（[EMIM][OAc]）和1-乙基-3-甲基咪唑六氟磷酸盐（[EMIM][PF]）对复合材料结构和光催化性能的影响。结果表明，不同离子液体的引入会影响MOFs材料的晶粒生长和光催化活性。其中，IL/MIL-68（In）-NH样品表现出最高的光催化活性。在最佳IL添加量（10 wt%）下，盐酸多西环素的去除率达到92%，动力学降解常数为0.00918 min⁻¹，是MIL-68（In）-NH的4.6倍。这种增强归因于低浓度下的有效吸附、活性位点的增加和有效的电荷转移的综合作用。此外，还研究了pH值和初始浓度的影响。最后，阐明了DOXH的光催化机理，并讨论了可能的中间产物和降解途径。鉴于IL/MIL-68（In）-NH优异的光稳定性和超快光降解性能，本研究为制备具有广泛实际应用价值的离子液体功能化MOFs开辟了新的前景。
