Кафедра технології неорганічних речовин, водоочищення та загальної хімічної технології (ТНР,ВтаЗХТ)

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Перегляд Кафедра технології неорганічних речовин, водоочищення та загальної хімічної технології (ТНР,ВтаЗХТ) за Автор "Dontsova, Tetiana"

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    Innovative inorganic technologies
    (Igor Sikorsky Kyiv Polytechnic Institute, 2022) Dontsova, Tetiana; Kutuzova, Anastasiya
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    Research on modified MOF materials for water pesticide pollutant purification
    (Igor Sikorsky Kyiv Polytechnic Institute, 2025) Zhou Zhentao; Dontsova, Tetiana
    Zhou Zhentao. Research on modified MOF materials for water pesticide pollutant purification. – Qualified scientific work on the rights of the manuscript. Dissertation for the degree of Doctor of Philosophy in the specialty 161 – Chemical Technologies and Engineering – National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", Kyiv, 2025. This dissertation is divided into two main parts: the first is the study of a Ti-MOFbased NH2-MIL-125/TiO2 composite photocatalytic system; the second is the study of an M88A@TA-X photo-Fenton catalytic system based on Fe-MOF modified with tannic acid and calcined. In the first part, the physicochemical structure of the NH2- MIL-125/TiO2 composites and their photocatalytic degradation performance of the insecticide imidacloprid in water are studied in detail. In the second part, the physicochemical structure of the M88A@TA-X series of materials, their photo-Fenton degradation performance of the herbicide atrazine, and their potential applications are studied in detail. This work investigates the photocatalytic activity of NH2-MIL-125/TiO2 composites synthesized at different dosage ratios of TiO2 and TPOT (the precursor of NH2-MIL-125). The results show that all NH2-MIL-125/TiO2 composites exhibit superior catalytic performance compared to pure NH2-MIL-125. Furthermore, we found that the material synthesized with a TiO2/TPOT ratio of 1:1 (NH2-MIL125/TiO2-100%) exhibited optimal catalytic activity (removing 100% of imidacloprid in 90 minutes). Increasing the TiO2/TPOT ratio from 0.35:1 to 1:1 showed animprovement in catalytic activity. However, further increasing the TiO2/TPOT ratio (from 1:1 to 2:1) did not lead to a further increase in catalytic activity. Therefore, this study used NH2-MIL-125/TiO2-100% as a representative material for characterization. X-ray diffraction spectroscopy (XRD), Infrared absorption spectrum (FTIR), and Thermogravimetric analysis (TGA) characterization demonstrated that TiO2 successfully incorporated into the NH2-MIL-125/TiO2 composite during its preparation, and that its incorporation did not disrupt the basic lattice and chemical structure of NH2-MIL-125. Scanning electron microscopy (SEM) results demonstrated that the TiO2 in the NH2-MIL-125/TiO2 composite was uniformly dispersed on the surface, facilitating contact between the catalyst and the pollutant during the reaction. Furthermore, Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS) results indicate that the band gap energy of NH2-MIL-125/TiO2 is 2.58 eV, lower than that of NH2-MIL-125 (2.68 eV) and TiO2 (3.36 eV). This suggests that NH2-MIL125/TiO2 has a wider spectral response range, thus favoring photocatalytic reactions. For a photo-Fenton catalyst (M88A@TA-X) prepared by modifying Fe-MOF (MIL-88A, denoted as M88A), this paper discusses the effects of different modification methods (including calcination temperature and whether tannic acid modification was used before calcination) on the photo-Fenton catalytic performance of the catalyst. Results showed that M88A@TA-2, modified with tannic acid and calcined at 200 °C, exhibited the best photo-Fenton activity, achieving 100% atrazine degradation within 30 minutes. Its reaction rate constant was 0.164 min⁻¹, 32.8 and 5.5 times that of M88A (0.005 min⁻¹) and M88A@TA (0.030 min⁻¹), respectively. M88A@TA-3 and M88A@TA-4, synthesized at higher temperatures, exhibited significantly reduced or completely inactivated activities. Furthermore, the catalytic activity of M88A-2(synthesized by calcining MIL-88A at 200 °C without TA modification) showed almost no increase compared with that of pure MIL-88A. These findings confirm that tannic acid modification and calcination at 200°C are crucial for enhancing the catalytic activity of MIL-88A. In addition to evaluating the photo-Fenton degradation rates of various materials, we also assessed their H2O2 consumption rates during the photoFenton reaction. Results show that M88A@TA-2 exhibits approximately fourfold higher H2O2 utilization efficiency than M88A, which holds great promise for its future practical applications. To investigate the mechanism underlying the excellent photo-Fenton activity of M88A@TA-2, the morphology and phase structure of the prepared material were characterized using SEM, Transmission electron microscopy (TEM), and BrunauerEmmett-Teller surface area analysis (BET) methods. Results indicate that M88A@TA2 exhibits a loose and porous structure compared to unmodified M88A. Furthermore, its surface area, at 44 m2 /g, is significantly higher than that of M88A (13 m2 /g). Furthermore, XRD, XPS, TGA, and FTIR characterizations demonstrate that M88A@TA-2 possesses a rich defect structure. The band structure of the prepared material was investigated using UV-Vis DRS and X-ray photoelectron spectroscopy (XPS) valence band spectroscopy. Results show that, thanks to defects regulating the band structure, the band gap energy of M88A@TA-2 (2.70 eV) is higher than that of M88A (2.94 eV), resulting in superior light absorption. This paper also discusses the mechanism by which M88A@TA-2 degrades atrazine in water via a photo-Fenton catalytic reaction. First, reactive oxygen species (ROS) scavenging experiments and electron paramagnetic resonance spectroscopy characterization confirmed that the primary reactive oxygen species in the photo-Fenton catalytic reaction are ·OH and 1O2. Ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was used to analyze samples from the photo-Fenton degradation of atrazine using M88A@TA-2, revealing the degradation products. Furthermore, the photo-Fenton degradation products of atrazine by M88A@TA-2 after the addition of different ROS scavengers were analyzed to infer the effects of different ROS on the degradation products. The results further confirm that ·OH and 1O2 are the dominant ROS in the M88A@TA-2 photo-Fenton system. The scientific novelty of the dissertation lies in the following provisions. A new composite photocatalyst, NH₂-MIL-125/TiO₂, based on metal-organic framework (MOF) semiconductors, has been synthesised. This combines the high light absorption capacity of NH₂-MIL-125 with the high oxidation capacity of TiO₂, allowing for greater photocatalytic activity. A new, simple synthesis method has been proposed which includes stages of modification with tannic acid and calcination. This method allows the synthesis of M88A@TA-2 material containing a large number of defects, demonstrating high photo-Fenton catalytic activity and extremely high H₂O₂ utilisation efficiency at low concentrations. This significantly reduces the energy consumption of the photo-Fenton process. Furthermore, a mechanism for the photo-Fenton decomposition of atrazine using the M88A@TA-2 catalyst has been proposed, providing valuable information for future research in the field of photo-Fenton catalysis. The practical significance of this work lies in establishing the optimal conditions for the synthesis of the NH2-MIL-125/TiO2 composite, which provides the basis for its future large-scale production. In addition, a simple method for the synthesis of thehighly efficient photo-Fenton catalyst M88A@TA-2 was developed as part of this study. It has been shown that the use of M88A@TA-2 increases the activity of the traditional photo-Fenton catalyst M88A by 32.8 times and increases the efficiency of the photocatalytic process when activated by hydrogen peroxide by 4 times, which indicates that M88A@ TA-2 effectively decomposes pollutants at extremely low H2O2 concentrations (1.76 mM). In addition, M88A@TA-2 demonstrated strong pH adaptability, which will reduce energy consumption, capital costs and reagent costs when treating complex real-world water environments, demonstrating its significant potential for applications in photo-Fenton processes.