No abstract

The paper presents a modification of titanium dioxide with fumed silica. The SiO2/TiO2 photocatalysts were obtained by the sol-gel method and then were calcined under an argon atmosphere. Various SiO2 weights (2–17.2 wt.%) were used in the materials’ preparation stage. The obtained samples were characterized using advanced analytical methods, such as FT-IR/DRS infrared spectroscopy, X-ray diffraction, SEM scanning electron microscopy, and UV-Vis/DRS spectroscopy. The BET specific surface area and zeta potential of samples were also measured. Based on the obtained results, it was observed that the modification of titanium dioxide with SiO2 effectively inhibited the increase in crystallite size of anatase and brookite during calcination and the decrease in specific surface area values. Moreover, the presence of SiO2 in the nanomaterials contributed to the increase in the size of specific surface area and the change in band gap energy values. The photocatalytic activity was determined based on the decomposition of methylene blue under UV irradiation. Thermal modification in an inert gas atmosphere significantly increased the dye removal rate. It should be noted that all the obtained SiO2/TiO2 photocatalysts showed higher activity compared to the starting TiO2. It was also found that the photocatalytic activity increased along with the increase in SiO2 content in the sample (up to 14.3 wt% of SiO2). The highest activity was recorded for SiO2(11.1%)/TiO2_400 and SiO2(14.3%)/TiO2_400 samples.

No abstract

Ethylcellulose polymer was used as a coating material in the preparation of controlled release fertilizers. The materials have been prepared with the use of an immersion method. The mass ratio of polymer to fertilizer was in the range of 0.165–0.285 and the layer thickness was in the range of 204–244 μm. Mechanical properties of the prepared materials were significantly better in comparison with the initial fertilizer. Measurements of time and the degree of release of mineral components from the obtained materials were determined with a standard method. Ethylcellulose-coated materials have met the requirements of controlled release fertilizers.

An investigation of the analytical separation of free urea from its additive compounds with H