Synthesis of Iron Oxide Magnetic Nanoparticles and Their Effect on Growth, Productivity, and Quality of Tomato

The influence of the structure, phase composition, textural and colloidal properties of magnetic iron oxides nanoparticles in the form of aqueous suspensions with a concentration of 0.001 and 0.01 mg/L on the growth, productivity of tomatoes and quality of its fruits after their foliar processing was shown. It was found that the maximum positive effect was observed during foliar treatment of tomato plants with aqueous suspensions of iron oxide samples with specific surface area (~52 and ~75 m2/g), two-level hierarchical structure, hydrodynamic diameters (~150 and ~180 nm) in stable aqueous suspensions (the absolute value of the ζ-potential is ≈ 30 mV)

A sol-gel synthesis and gas-sensing properties of finely dispersed ZrTiO4

The transparent titanium-zirconium-containing gel was obtained using heteroligand coordination compounds (namely, alkoxoacetylacetonates) as the precursors. The high-dispersive system “ZrTiO4 – carbon”, formed after drying of such gel and carbonization of the obtained xerogel, was used to study the evolution of microstructure for the product (ZrTiO4) during thermal treatment in air for 1 h in the temperature range from 500 °C to 1000°С. It was stated that the formation of crystalline phase occurred in the narrow range 690-730°С. The thermal treatment at 500 °C and 600°С allowed obtaining micro- and mesoporous X-ray amorphous products of the composition ZrTiO4, with the specific surface area falling in the range 82–150m2/g. At the higher temperatures the single-phase nanocrystalline powder was prepared (the specific surface area amounted to 2.5–15m2/g). Particle coarsening took place more extensively at temperatures ≥700°С was shown. For the ZrTiO4 nanopowder crystallized under the mildest conditions at the temperature of 700 °C, chemoresistive gas-sensitive properties were studied for the first time. The material showed a high reproducible response at 1–20% O2 and 200–10,000 ppm H2 at a relatively low detection operating temperature of 450 °C

The Structure and Properties of TiO2 Nanopowders for Use in Agricultural Technologies

TiO 2 nanopowder has been prepared with aqueous chemical synthesis for use in agriculture. A commercial nanopowder was taken for comparison. A comprehensive study of the phase composition, morphology, and structure of both nanopowders was carried out using methods of X-ray phase analysis, Raman spectroscopy, scanning electron microscopy, ultra-small-angle and small-angle neutron scattering, and low-temperature nitrogen adsorption. A comparison of the photocatalytic activity of these powders was carried out. Aqueous suspensions of these powders were used for the pre-sowing treatment of white cabbage seeds. A positive effect of suspensions of both titanium dioxide powders at a concentration of 0.3 g/l on the germination and biometric characteristics of plant seedlings of cabbage seedlings was revealed. As a tendency, we can note the more beneficial effect of the synthesized powder, which has a high specific surface area and porosity, is weakly crystallized in the anatase phase, and has a three-level fractal structure. No direct effect of photocatalytic activity on the germination and growth characteristics of plant seedlings was found