Nanoparticles and deposited zinc oxide layers were successfully obtained using the polymer precursor method. Glycerol or ethylene glycol with and without the addition of citric acid were used as the main precursor component. Powders and deposited oxide layers were obtained after annealing at 400 and 600 ℃. The properties of the obtained ZnO were investigated using various spectral and physicochemical methods. The effect of polymer precursor solution composition and synthesis temperature on various properties was analyzed. The formation of highly crystalline zinc oxide was confirmed by XRD, as well as the effect of the composition and annealing temperature on the particle size, optical and electrical properties. The synthesized powders contained crystallites ranging in size from 12.3 to 42 nm. FTIR spectra showed the presence of small amounts of organic contaminants in the powders when using polymer precursor formulations without citric acid, even when annealed at 600 ℃. The obtained deposited zinc oxide films analyzed by SEM and AFM showed the formation of granular porous structures as well as zinc oxide characteristic nanocolumns and nanorods with mean grain size values from 50 to 213 nm and RMS surface roughness values from 8.62 nm to 48.33 nm. The electrical characteristics of the powders depended on the size of crystallites and the presence of impurities, the presence of photosensitivity in varying degrees was registered in all obtained samples. The results demonstrate possible ways to obtain a variety of zinc oxide structures with different properties and suggest applications in various semiconductor sensing applications.

The physicochemical properties of SnO 2 obtained by different methods (sol–gel, solvothermal and CVD synthesis) from different precursors were investigated. The synthesized samples were characterized by X-ray diffraction analysis, electron spectroscopy, FTIR, low-temperature nitrogen adsorption–desorption and their optical bandgap and volt-ampere characteristics were determined. It was shown that the synthesis method and its parameters have a significant effect on the properties of the obtained SnO 2 powders. The type of reaction medium significantly affects structural and adsorption characteristics of samples. SnO 2 synthesized by the solvothermal method is characterized by the smallest crystallite sizes, larger specific surface, and more diverse structural characteristics in comparison with the powders obtained by sol–gel and CVD methods. Mesoporous powders of tin (IV) oxide were obtained using sol–gel method, macroporous SnO 2 monocrystalline powders were produced by CVD method. The found values of the optical bandgap for the tin (IV) oxide, obtained by different methods, differ from the theoretical bandgap value. The influence of all parameters on the electrical properties of SnO 2 was observed.

The efficiency of agricultural use of soils depends directly on their quality indicators, which include an extended set of characteristics: from data of the environmental situation to the component composition of the soil air. Therefore, for a more complete survey of agricultural land in order to determine their qualitative indicators and subsequent application, it is necessary to carry out comprehensive monitoring while simultaneously studying the characteristics of soils and their air composition. The article is devoted to the literature analysis on the remote monitoring of soils and soil air. Particular attention was paid to the relationship between soil type and soil air composition and it was found that the soil air composition (in the combination with pH and humidity parameters) can assess the type, quality and environmental condition of soils. Since when developing a remote monitoring system of soil air soil moisture and soil structure significantly affect the processes occurring in soils, and ultimately the quantitative composition of soil air, it is very important to know the dependence of the soil air composition on the type and quality of the soil itself, the influence of moisture, structure and other parameters on it. It was shown that the use of sensors is a promising direction for the development of the soils and soil air remote monitoring. It was indicated that soil and soil air remote monitoring in real time will provide reliable, timely information on the environmental status of soils and their quality. Commercial sensors that can be used to determine CO2, O2, NOx, CH4, CO, H2 and NH3 were considered and the technique for sensor signal processing was chosen. A remote monitoring system with the use of existing commercial sensors was proposed, the movement of which can be realized with the help of quadcopter, which will allow parallel scanning of the soils and the land terrain. Such a system will make it possible to correctly assess the readiness of soils for planting, determine their intended use, correctly apply fertilizers, and even predict the yield of certain crops. Thereby, this approach will create a modern on-line system for full monitoring of soil, land and rapid response in the case of its change for the agro-industrial sector.