MICROCHIMICA ACTA
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2025
·Vol. 192
·期 2
·1-11
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IF 5.3
Tang Jiazhen,Chen Jiawei,Xu Ruijie,Xu Junhui,Peng Xiaolun,Wang Yazhen
An electrochemical sensor is presented for the detection of the chloramphenicol (CAP) based on a bimetallic MIL-101(Fe/Co) MOF electrocatalyst. The MIL-101(Fe/Co) was prepared by utilizing mixed-valence Fe (III) and Co (II) as metal nodes and terephthalic acid as ligands with a simple hydrothermal method and characterized by SEM, TEM, XRD, FTIR, and XPS. Electrochemical measurements such as electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV) showed that bimetallic MIL-101(Fe/Co) had the faster electron transfer, larger electroactive area, and higher electrocatalytic activity compared with their monometallic counterparts due to the strong synergistic effect between bimetals. Inspired by these results, the MIL-101(Fe/Co)-based sensor was used to detect CAP. Some experiment parameters of pH, Fe and Co molar ratio, MIL-101(Fe/Co) volume, and DPV quiet time were optimized. The direct reduction mechanism of CAP was verified to involve four electrons and four protons process. Finally, the sensitive and selective CAP detection in the concentration range 1 to 200 μM with a detection limit of 0.3 μM was realized by the proposed sensor. The satisfactory recoveries in tap water and lake water indicated the practicability of the proposed electrochemical sensor. It is expected that this work may open up a paradigm for the preparation of MOF-based electrode modifiers with desired electrocatalytic performance for environmental pollution monitoring.
研究领域:
分析化学
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环境科学
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DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2025
·
IF 3.5
Tongxin Xiao,Kangyue Qiao,Guodong Hao,Songyao Du,Yue Wang,Chao Sui
This study employed a solvothermal method to prepare an NH 2 -MIL-101(Fe, Co) bimetallic organic framework composite catalyst aimed at enhancing the photocatalytic reduction performance of Cr(VI). The experimental results show that introducing Co into the single-metal NH 2 -MIL-101(Fe) does not alter the material's octahedral structure. However, the bimetallic synergistic effect shifts the light absorption range to the red end of the spectrum, reduces the bandgap, and significantly improves carrier separation efficiency. Under visible light irradiation, the NH 2 -MIL-101(Fe, 0.15Co) catalyst exhibited outstanding photocatalytic performance, achieving a reduction efficiency of 94.7% for Cr(VI) within 40 minutes and 100% within 50 minutes, with a reaction rate constant 4.7 times that of the single-metal NH 2 -MIL-101(Fe). Free radical capture experiments further revealed that ·O 2 - is the key active species in the Cr(VI) reduction process, while photo-generated holes in the valence band can oxidise OH - to ·OH, synergistically participating in the reaction. Additionally, cyclic stability experiments showed that the catalyst maintained 85.8% reduction efficiency after five cycles, demonstrating excellent stability and practical application potential.
研究领域:
环境科学
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催化
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材料科学
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化学工程
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高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Liu-Xi Yang,Jia-Cheng E. Yang,Ming-Lai Fu
In this study, porous magnetic CoFe 2 O 4 nanocrystals (NCs) were successfully synthesized by using bimetal-organic framework (MOF) as a precursor, and used as catalysts to activate peroxymonosulfate (PMS) for the removal of chloramphenicol (CAP) in the solution. The structure and physicochemical properties of CoFe 2 O 4 NCs were thoroughly examined by a series of characterization techniques. The results revealed as-synthesized CoFe 2 O 4 had a nanorod-shaped structure with high specific surface area (83.00 m 2 g −1 ) and pore volume (0.31 cm 3 g −1 ). Furthermore, the degradation efficiency (100%) and the removal of total organic carbon (68.09%) were achieved after 120 min with 0.1 g/L CoFe 2 O 4 NCs, 2 mM PMS and 10 mg/L CAP at pH of 8.20. In addition, effects of catalyst dosage, PMS dosage, initial pH values, CAP concentration and co-existing anions as well as natural organic matters in the solution on the degradation efficiencies were studied and all the removal can be well fitted with pseudo-first-order kinetic model (R 2 > 0.96). Sulfate radicals (SO 4 •− ) and hydroxyl radicals (HO•) were proved to be two main reactive species for CAP removal in CoFe 2 O 4 /PMS system based on quenching experiments. CAP was degraded by the main pathways of dichlorination, denitration, decarboxylation , hydroxylation, ring cleavage and chain cleavage on CoFe 2 O 4 /PMS system through high performance liquid chromatograph-mass spectrometry analysis. We believe that this study would be very meaningful to promote the applications of MOFs-derived catalysts on the SO 4 •− based advanced oxidation processes (SR-AOPs) for the environmental remediation.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Ziyi Xiao,Rui Wu,Tingting Shu,Yingxi Wang,Ling Li
In order to further improve the catalytic performance of MIL-101, cobalt-doped MIL-101(Fe,Co) was synthesized by solvothermal method. By adjusting the ratio of cobalt doping, the MIL-101(Fe,Co 20% ) with the best catalytic activity was obtained. The activation performance of MIL-101(Fe,Co 20% ) for peroxymonosulfate (PMS) was studied using Rhodamine B (RhB) as a pollutant model. The experimental results proved MIL-101(Fe,Co 20% ) with much better catalytic performance than MIL-101(Fe), which can degrade more than 99% of RhB within 15 min. The effects of initial solution pH and coexisting anions in water on the degradation of RhB were further discussed. The results showed that MIL-101(Fe,Co 20% ) was with excellent stability and degradation efficiency can still keep above 90% after five cycles. The free radical quenching experiments were further studied to explore the degradation mechanism. It can be concluded that SO 4 - · was the main active free radical for the degradation of RhB. The possible intermediate products in the degradation process of RhB were analyzed by LC-MS. Combined with the comparison of XPS before and after the reaction, the possible reaction mechanism of RhB degradation process was inferred.
研究领域:
环境科学
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材料科学
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催化化学
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DOI
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 24
·16727-16735
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IF 3.9
Huizhong Wu,Qiong Yi,Xiang Li,Yingxi Wang,Ling Li
Low catalytic efficiency and catalyst recovery are the key factors limiting the practical application of advanced oxidation processes. In this work, a core–shell magnetic nanostructure Fe3O4@MIL-101(Fe, Co) was prepared via a simple solvothermal method. The core–shell structure and magnetic recovery performance were characterized by various technologies. The results of dye degradation experiments proved that within 10 minutes, the Fe3O4@MIL-101(Fe, Co)/PMS system can degrade more than 95% of 10 mg per L Rhodamine (RhB) at an initial pH of 7, which possesses higher catalytic activity than the Fe3O4/PMS system and the MIL-101(Fe, Co)/PMS system. The effects of initial solution pH and coexisting anions in water on the degradation of RhB were further discussed. The results showed that Fe3O4@MIL-101(Fe, Co) displayed excellent degradation efficiency in a wide pH range of 3–11 and capability of resisting coexisting anions. It is worth mentioning that after five cycles, the RhB removal rate can still be maintained at over 90% after 10 minutes of reaction. Free radical quenching experiments were further studied, confirming that ˙OH and SO4−˙ were involved in the degradation of RhB, while the dominating active free radical was SO4−˙. The possible reaction mechanism of the RhB degradation process was also inferred.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
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