Photocatalytic Properties of Different Morphology TiO2 Nanostructures Modified with Various Modificators
Modern Materials and Manufacturing 2019: Book of Abstracts 2019
Reinis Drunka, Jānis Grabis, Dzidra Jankoviča, Aija Krūmiņa, Dzintra Ārija Rašmane, Ints Šteins

In recent decades, science has sought to research the properties of materials with a smaller particle size. Since the 1970s TiO2 has become one of the most widely studied photocatalysts in the world. TiO2 exhibits very high photocatalytic activity under the UV radiation, but still this photocatalyst activity is inadequate in visible light. It is necessary to reduce the width of the band gap (for pure TiO2 anatase ~ 3.2 eV). This can be done by introducing a small amount of atoms or molecules of other elements into a TiO2 anatase crystalline in place of oxygen vacancies. Solar cells made from various modified TiO2 nanostructures have shown that efficiency increased from 7% in 1991 to 12-13% at present and with the use of such materials in direct sunlight their efficiency is almost 2 times higher than in the visible light because solar radiation also includes the spectral part of UV radiation. The efficiency of photocatalysts can also be improved by increasing the specific surface that can be successfully realized by forming TiO2 photocatalysts with different nanostructured surface morphology as nanotube and nanopurus coatings or nanofibers. Modified TiO2 is able to degrade harmful organic compounds in less harmful, therefore, it has a wide range of possibilities for use in industrial plants in wastewater treatment systems [1;2]. Previous studies have described many different methods for obtaining modified TiO2 nanopowders, but the practical use of such materials is complicated due to the problematic removal of the photocatalyst nanoparticles from the treated solution. Practical applications are surface-mounted TiO2 photocatalysts. Prospecting to achive the aims of the research are anodization, micro plasma electrolytic oxidation and microwave-assisted synthesis methods combined with the modification of the chemical composition of the photocatalysts. The modification of TiO2 with Au, Pt, Pd, Ag, WO3, S, Eu2O3 nanoparticles is effective in increasing photocatalytic activity, however, the activity also depends on the modifier content, TiO2 morphology and particle size. It is determined that all obtained samples exhibit photocatalytic properties but their activity is different. Depending on the type of nanostructure the amount of degraded MB with the same modifier content increases in the following order: nanoporous coatings < nanotubes coatings < nanofibers. In addition, 0.1 g of modified TiO2 nanofibers are capable to degrade the same amount of MB per hour as similarly modified TiO2 nanotubes coatings or TiO2 nanoporous coatings with a surface area of 1 cm2 in three hours under both UV and VIS irradiation.

TiO2, nanotubes, nanopores, nanofibers, photocatalysis.

Drunka, R., Grabis, J., Jankoviča, D., Krūmiņa, A., Rašmane, D., Šteins, I. Photocatalytic Properties of Different Morphology TiO2 Nanostructures Modified with Various Modificators. In: Modern Materials and Manufacturing 2019: Book of Abstracts, Estonia, Tallinn, 23-26 April, 2019. Tallinn: 2019, pp.1-1.

Publication language
English (en)
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