Characterization and Photocatalytic Properties of Titanium Dioxide Nanoparticles at Low Synthesis Temperatures

Purpose of the study. Determination of the dimensional characteristics, elemental, phase and chemical composition of titanium dioxide nanoparticles synthesized by the hydrothermal method using low temperatures up to 100 ° C, as well as the study of their photocatalytic activity.

Methods. Сharacterization of titanium dioxide nanoparticles synthesized at low-temperature conditions using scanning electron microscopy with an energy dispersive analysis attachment, structural chemical analysis using infrared Fourier spectroscopy to identify organic impurities, and determine efficient decarbonization methods by comparing the analysis results of samples after washing with different polar and non-polar solvents; a study of the photocatalytic activity of synthesized powders of titanium dioxide nanoparticles using the example of photodegradation of methylene blue solution depending on the concentration and the size characteristics of the particles.

Results. Titanium dioxide particles in the form of nanopowder were obtained by the hydrothermal synthesis method using low temperatures followed by washing with polar and non-polar solvents and subsequent thermal annealing. According to spectral analysis and scanning electron microscopy data, after washing with solvents and the decarbonization methods used, a decrease in impurities of carbon compounds in the substance from 68% to 4% is achieved. The synthesized particles had spherical and ellipsoidal shapes with an average size of 24 nm. The high photocatalytic activity of the synthesized nanoparticles was proved by the example of methylene blue degradation under ultraviolet radiation.

Conclusion. As a result of complex analysis by nanoinstrumental methods, titanium dioxide nanoparticles obtained by the hydrothermal method at low-temperature conditions up to 100 °C were characterized. The particles have an average size of 24 nm and a rounded shape. The efficiency of combined washing from organic impurities with polar and non-polar solvents and thermal annealing of the synthesized samples for decarbonization has been proven. Upon annealing, the anatase structure of the crystal lattice was preserved. Nanoparticles exhibit high photocatalytic activity in the photodegradation of methylene blue under ultraviolet irradiation. Acceleration of the reaction rate of photocatalysis contributes to the achievement of concentration in the solution and a decrease in their size.

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