Mikayel S Aleksanyan

In this work, a high-sensitive flexible sensor based on the SnO₂ nanoparticles decorated with the multi-walled carbon nanotubes (MWCNTs) was fabricated by a simple and cost-effective centrifugation method for hydrogen peroxide vapour (HPV) detection. Morphological, composition, structural, and HPV sensing studies of the film were thoroughly conducted. Scanning electron microscopy (SEM) revealed the presence of MWCNTs in the SnO₂ material and energy dispersive x-ray (EDX) elementary analysis determined the actual concentration of carbon elements (24.47 wt%) in the SnO₂:MWCNTs material with pronounced peaks of C, O, and Sn. Elemental mapping analysis showed the nearly homogeneous distribution of the elements while x-ray diffraction analysis (XRD) confirmed the diffraction peaks of tin oxide and carbon. The HPV sensing behaviour of the flexible SnO₂:MWCNTs sensor was investigated in the temperature range of 25 °C–150 °C towards 1.5–56 ppm HPV under ultraviolet (UV) irradiation. The flexible sensor had a fairly high response (44) to 1.5 ppm of HPV concentration at room temperature (RT). The fabricated SnO₂:MWCNTs based sensor was capable of detecting extremely low concentrations of HPV, thus being a potential candidate for use in real environments.

In this report, a Fe₂O₃:ZnO sputtering target and a nanograins-based sensor were developed for the room temperature (RT) detection of hydrogen peroxide vapor (HPV) using the solid-state reaction method and the radio frequency (RF) magnetron sputtering technique, respectively. The characterization of the synthesized sputtering target and the obtained nanostructured film was carried out by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray (EDX) analyses. The SEM and TEM images of the film revealed its homogeneous granular structure, with a grain size of 10–30 nm and an interplanar spacing of Fe₂O₃ and ZnO, respectively. EDX spectroscopy presented the real concentrations of Zn in the target material and in the film (21.2 wt.% and 19.4 wt.%, respectively), with a uniform distribution of O, Al, Zn, and Fe elements in the e-mapped images of the Fe₂O₃:ZnO film. The gas sensing behavior was investigated in the temperature range of 25–250 °C with regards to the 1.5–56 ppm HPV concentrations, with and without ultraviolet (UV) irradiation. The presence of UV light on the Fe₂O₃:ZnO surface at RT reduced a low detection limit from 3 ppm to 1.5 ppm, which corresponded to a response value of 12, with the sensor’s response and recovery times of 91 s and 482 s, respectively. The obtained promising results are attributed to the improved characteristics of the Fe₂O₃:ZnO composite material, which will enable its use in multifunctional sensor systems and medical diagnostic devices.

This study aimed to develop a high-performance hydrogen flexible sensor based on multi-walled carbon nanotube (MWCNT):SnO ₂ material. The MWCNT:SnO ₂ thin film was deposited onto a flexible polyimide substrate by the electron-beam deposition method to perform the low temperature detection of hydrogen. The thickness and surface morphology of the sensing layers have been determined by the thickness measuring profilometer and the scanning electron microscope (SEM), respectively. The flexible MWCNT:SnO ₂ sensor exhibited excellent sensitive characteristics to hydrogen in a range of 25–3000 ppm. H ₂ sensing parameters like sensor response, recovery, and response times were investigated at different operating temperatures. The minimum response and recovery times of the sensor corresponding to 1000 ppm H ₂ concentrations were found to be 37 and 554 s, respectively. The investigated sensing parameters demonstrate that this work can provide the possibility of a versatile route to fabricate flexible hydrogen sensor with high sensitivity and selectivity, which demonstrates its great potential in hydrogen leakage monitoring.

In this paper, the ZnO target was synthesized by the solid-state reaction method and a nanostructured thin film was deposited by the RF (radio frequency) magnetron sputtering method on a Multi-Sensor-Platform. The obtained ZnO nanostructured film was investigated as the sensing material. Energy-Dispersive X-ray (EDX) analysis indicated the existence of La in the synthesized ZnO material. Scanning Electron Microscope (SEM) images of the film showed the grain sizes in the range of 20–40 nm. Sensor performance characteristics such as a dynamic response, response and recovery times, and ethanol detection range were investigated at 50–300 °C. A sensitivity was observed at extremely low concentrations of ethanol (0.7 ppm). The minimum response and recovery times of the sensor corresponding to 675 ppm ethanol vapor concentration at 250 °C were found to be 14 s and 61 s, respectively. The sensor showed a high response, good selectivity, fast response/recovery behavior, excellent repeatability toward ethanol vapor, and low sensitivity toward humidity. These characteristics enable the use of a ZnO based sensor for ethanol detecting applications.

Flexible gas sensors based on the SnO2❬Co❭/MWCNT (multi-wall carbon nanotubes) structure have been fabricated. The results of studies of the

A nanostructured gas sensors made of the Fe2O3:ZnO (60 : 40 wt %) composition were fabricated. The SEM image of the gas sensitive film showed that the part

In this work, the morphology of Fe2O3:ZnO (60 : 40 mol %) film and gas sensing characteristics to ammonia vapors at different operating temperatures were i

A sensor sensitive to acetone vapors based on a Fe2O3❬Sn❭ metal oxide solid solution was fabricated by high-frequency magnetron sputtering. T

A technology has been developed for obtaining a semiconductor solid solution SnO2 + Nb2O5 (80 : 20 wt %) and for manufacturing a thin-film nanoscale resist

The sensitivity of gas sensors made of doped SnO2:Co metal oxide for the detection of hydrogen peroxide vapors in the environment was studied using current