[en] Results of last years investigations of different metal oxide semiconductor photo electrodes for photoelectrochemical hydrogen production by method of water photo electrolysis are presented. It is shown that the investigations concerning the development of new photo electrodes made of solid solutions and more complicate multicomponent compositions are most promising. Possibilities of the use of porous and nanocrystalline oxide photo electrodes in photo electrochemistry are discussed also. Photo electrolysis setups for the photoelectrochemical conversion of solar energy in hydrogen are described

[en] LPG and butane gas sensor was manufactured. Its sensitive element is In₂O₃:Ga₂O₃ (96:4 wt.%) nano size film covered by a thin palladium catalytic layer. The technology of deposition of In₂O₃:Ga₂O₃ (96:4 wt.%) films on glass-ceramic substrates by high-frequency magnetron sputtering was developed. The surfaces of prepared films were investigated by scanning electron microscopy; the thicknesses of films were measured. The response of the glass-ceramic / In₂O₃:Ga₂O₃ (96:4 wt.%)/Pd structure depending on the thickness and sizes of grains of the film was investigated. The technological modes of sputtering were found which provide films with optimum parameters

[en] In₂O₃:Ga₂O₃ (96:4 wt.%) nanosize films were deposited on glass-ceramic substrates by high-frequency magnetron sputtering. The surfaces of prepared films were investigated by scanning electron microscopy, the sizes of grains were determined, and the thicknesses of films were measured. The gas sensing structures was completed through ion-beam sputtering deposition of very thin palladium catalytic layer and gold interdigitated ohmic contacts on the prepared In₂O₃:Ga₂O₃ films. The response of the glass-ceramic/In₂O₃:Ga₂O₃ (96:4 wt.%)/Pd structure to different concentrations of the propane-butane mixture and also to methane at temperatures of a working body from 200 to 350 degree was investigated

[en] A technology has been developed for the production of SnO₂ + Nb₂O₅ (80 : 20 wt.%) semiconductor solid solution and the thin-film, nanoscaled resistive sensor based on it. The gas sensitivity characteristics of the sensor to different concentrations of liquefied petroleum gas (LPG) were investigated. The SnO₂ sensor showed sensitive to this gas from temperatures up to 250°C in the presence of ultraviolet irradiation. The 250°C was chosen as the operating temperature and at this temperature the sensor showed sufficient sensitivity, high speed and repeatability of response over time. In the future the SnO₂ structure can be used in security systems that detect LPG and measure its concentrations

[en] In this work, the morphology of Fe₂O₃:ZnO (60:40 mol.percent) film and gas sensing characteristics to ammonia vapors at different operating temperatures were investigated. The SEM investigation of the surface of sensitive film of Fe₂O₃:ZnO showed that the grain size in the film was about 50 nm. The sensor showed sensitivity to ammonia vapors starting at 200 ℃ and the operating temperature was chosen as 250℃. The low detection limit of the sensor based on Fe₂O₃:ZnO is quite low (∼14 ppm) and at this concentration of ammonia vapors the resistance of the sensor changed more than 1.5 times. The enhanced parameters of the Fe₂O₃:ZnO based sensor will allow using this structure in ammonia detecting devices

[en] A nanostructured sensor for the detection of hydrogen peroxide vapors was manufactured. A gas sensitive film based on ZnO metal oxide doped with 2 at.% La was obtained by high-frequency magnetron sputtering method. In the temperature range of 25℃ to 200℃, the impedance and current-voltage characteristics of the ZnO sensor were studied with and without hydrogen peroxide vapors. The equivalent electrical circuit for the the sensor was suggested and the parameters of its elements were estimated. The fitting curves were calculated based on the analysis of the frequency characteristics of the complex impedance. It was shown that the sensitivity of the manufactured sensor mainly depends on the processes occurring on the surface of the semiconductor film. The effect of the change of the target gas concentration on the sensitivity of the ZnO sensor was studied

[en] A flexible gas sensor based on the SnO₂/MWCNT (Multi-Walled Carbon Nanotube) structure was developed in this work. The results of the investigations of the gas sensing characteristics of the prepared SnO₂/MWCNT sensor to hydrogen peroxide vapors at different operating temperatures were presented. The thickness of the sensitive film was measured and it was about 75 nm. The sensor showed sensitive to hydrogen peroxide vapors starting at room temperature. The resistance of the sensitive layer in the presence of 4.4 ppm hydrogen peroxide vapor increased more than 22 times at 25℃. At this concentration of hydrogen peroxide vapor, the maximum sensitivity value was observed at 75℃, where the sensor resistance increased approximately 50 times

[en] A ceramic target made of SnO₂ metal oxide doped with Co was synthesized in result of solid phase reaction for magnetron sputtering. A hydrogen peroxide vapour sensitive thin films were deposited by high-frequency magnetron sputtering method. Capacitance-voltage characteristics of the resistive film with the presence of hydrogen peroxide vapour were measured at room temperature under the influence of UV irradiation. In result the sensitivity of the film is increased by about 1.6 times. The possibility of negative capacitance of SnO₂:Co sensor is shown

[en] Nanostructured gas sensors were manufactured based on the Fe₂O₃:ZnO structure. The SEM image of the sensitive film of the sensor showed that the grain sizes in the film were in the range of 20–50 nm. The gas sensing characteristics of the sensors at different operating temperatures (50–250°C) and in the presence of different concentrations of hydrogen (75– 2000 ppm) were investigated. The sensors showed sensitivity to hydrogen starting from a temperature of 50°C, and the maximum response was observed at 100°C, where the response was more than 5000. The optimal combination of gas sensing parameters of the sensor was observed at 200°C

[en] The semiconductor photoanodes made of thin film titanium oxide were prepared by anodization of titanium plates in hydrofluoric acid solution at direct voltage at room temperature. The influence of the change of titanium oxide film growth conditions (concentration of hydrofluoric acid, voltage, duration of anodization process) and subsequent heat treatment of films on a photocurrent and current-voltage characteristics of photo-electrodes were investigated. The influence of the electrolyte concentrations change on photoelectrochemical behaviour of thin film titanium oxide photoanodes was investigated. (authors)