DEVELOPMENT OF EFFICIENT ADSORPTION-CATALYTIC NANOSYSTEMS FOR THE TREATMENT OF WASTEWATER OF OIL REFINING ENTERPRISES

ABSTRACT

The development of new types of adsorption–photolytic nanomaterials with improved properties in porous nanomaterials production and environmental remediation is of great importance. This study investigates the one-step sol-gel synthesis of TiO₂-based nanostructured materials, focusing on pore formation mechanisms and their properties, the mechanisms of pore formation, and the properties obtained as a result of the formation of 3d-metals. Using the sol-gel method, nanostructured TiO₂ materials were synthesized with particle sizes ranging from 50-100 nm, exhibiting enhanced photocatalytic and adsorption properties. The structural and morphological properties were analyzed using SEM, EDX, and Raman spectroscopy. The results demonstrate high-purity TiO₂ (98.6%) with improved photocatalytic activity under UV light, offering a promising solution for environmental remediation.

АННОТАЦИЯ

Разработка новых типов адсорбционно-фотолитических наноматериалов с улучшенными свойствами для производства пористых наноматериалов и очистки окружающей среды имеет большое значение. В докладе рассматриваются процессы и основы одностадийной золь-гель программы практического применения формирования неструктурированных пор на основе TiO₂, механизмы порообразования и свойства, получаемые в результате формирования 3d-металлов. С помощью золь-гель метода синтезированы наноструктурированные материалы TiO₂ с размером частиц от 50 до 100 нм, обладающие улучшенными фотокаталитическими и адсорбционными свойствами. Структурно-морфологические свойства исследовались с помощью СЭМ, энергодисперсионной рентгеновской спектроскопии и рамановской спектроскопии. Результаты демонстрируют получение TiO₂ высокой чистоты (98,6%) с улучшенной фотокаталитической активностью в УФ-свете, что является перспективным решением для очистки окружающей среды.

Keywords: titanium dioxide, sol-gel method, photocatalysis, wastewater treatment, nanomaterials, SEM analysis, Raman spectroscopy, adsorption.

Ключевые слова: диоксид титана, золь-гель метод, фотокатализ, очистка сточных вод, наноматериалы, анализ методом СЭМ, спектроскопия Рамана, адсорбция.

Introduction

In recent years, the rapid development of industry and the application of modern technologies for addressing environmental challenges have gained increasing importance worldwide. The production of competitive and environmentally friendly products is becoming a strategic priority, while the implementation of innovative approaches based on nanotechnology is expected to play a key role in economic growth over the coming decades. Along with this, the accelerated development of industrially significant products using nanotechnology and the improvement of their physicochemical properties remain at the forefront of modern scientific research. [1][3][8]

Porous nanomaterials, in particular, have attracted significant attention due to their potential to create new types of sorption–photocatalytic systems with enhanced properties for solving a wide range of environmental protection problems. The efficiency of modern wastewater treatment technologies, especially those based on porous nanostructured materials, has been shown to increase substantially. In Uzbekistan as well, modernization of industrial enterprises and the introduction of advanced technological approaches are creating opportunities for the production of new materials with improved environmental performance.[2][4]

Therefore, the main objective of this study is to develop highly efficient adsorption–catalytic nanosystems for the treatment of wastewater from oil refining enterprises, to investigate their physicochemical properties, and to evaluate their potential applications in addressing urgent problems of environmental protection.[5]

Method

Using sol-gel technology, TiO₂ (titanium dioxide)-based nanomaterials were synthesized, and their structural, physical, and chemical properties were studied in depth. The materials used for the synthesis of TiO₂ by the sol-gel method and all the chemicals used were of analytical purity, so they were used without additional purification.[6][8]

Table 1.

Materials used for the synthesis of TiO₂ by the sol-gel method

The sol-gel synthesis was performed by dropwise addition of a 50 ml mixture of isopropyl alcohol and water to a 0.1 M TTIP solution under constant stirring at 250 rpm. The addition rate was controlled at 1 drop per 25 seconds to ensure homogeneous gel formation. The resulting sample was left to settle for 10 hours. The extracted sample was filtered. It was washed two to three times in distilled water. After that, the sample was placed in a drying oven (GS-101 series, temperature: +10 °C ~ 300 °C, volume: 80-100 l, dimensions (external): about 70x60x85 cm) for drying at a temperature of 80 °C for 2-3 hours. The dried residue was ground by hand and then placed in a furnace (Nabertherm 30-3000 °C Made in Germany) at 500 °C for 4 hours for calcination.

Morphological studies were carried out using a scanning electron microscope JEOL JSM-IT200 (Japan), Raman spectra of the synthesized nanosystems were recorded on a Renishaw InVia Reflex Raman spectrometer (UK) with a 532 nm excitation laser and elemental composition was determined by energy dispersive X-ray spectroscopy (Oxford Instruments EDX system, UK) attached to the SEM instrument. The microstructure and morphological properties of TiO₂ nanomaterials synthesized by the sol-gel method were determined by SEM analysis, their spectral properties were determined by EDX analysis, their quantitative ratios were shown, and the structural properties of the TiO₂ sample were analyzed using Raman spectroscopy.

Results And Discussion

The microstructure and morphological properties of TiO₂ nanomaterials synthesized by the sol-gel method were systematically studied. In general, SEM analysis showed that TiO₂ nanomaterials synthesized by the sol-gel method are composed of nanoparticles, the size of which is in the range of 50-100 nm. From image A to image D, the structure becomes denser and the surface becomes smoother. These morphological changes can significantly affect the physicochemical properties of the material, including photocatalytic activity and mechanical stability.

Figure 1. (a-d) shows SEM images of TiO₂ nanoparticles at different magnifications (2-20 μm), revealing a denser and smoother surface morphology with increasing magnification, which enhances photocatalytic efficiency

At the same time, EDX analysis of the TiO₂ sample synthesized by the sol-gel method was also carried out. The results showed that the TiO₂ Ka (4.52 keV) peaks indicate the presence of Ti and O, confirming that these elements are important components of the sample. It can be seen that the purity of TiO₂ was determined as 98.6%.

Figure 2. EDX image of TiO₂ nanomaterial

Raman analysis of the synthesized TiO₂ nanomaterial was also performed, in which the structural properties of the TiO₂ sample synthesized by the sol-gel method were analyzed using Raman spectroscopy. The main peaks detected in Raman are at frequencies of 369 cm^-1, 609 cm^-1, 723 cm^-1, and 840 cm^-1, which indicate changes in the phase composition of TiO₂.

Figure 3. Raman spectrum of TiO₂ nanomaterial synthesized by the sol-gel method

Conclusion

The sol-gel synthesis of TiO₂ nanomaterials yielded high-purity (98.6%) nanoparticles with sizes of 50-100 nm, exhibiting enhanced adsorption and photocatalytic properties. The optimized synthesis conditions, confirmed through SEM, EDX, and Raman analyses, provide a scalable approach for producing efficient nanosystems for wastewater treatment in oil refining industries. Future work will focus on doping TiO2 with 3d-metals to further enhance its photocatalytic performance.

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