scholarly journals Nano Ag-DopedIn2O3Thick Film: A Low-TemperatureH2SGas Sensor

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
D. N. Chavan ◽  
G. E. Patil ◽  
D. D. Kajale ◽  
V. B. Gaikwad ◽  
P. K. Khanna ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Thick Films ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Ethanol Vapour ◽  
Nano Silver ◽  
Sensitivity And Selectivity ◽  
Response And Recovery ◽  
Surface Modified ◽  
Sensing Performance

Thick films of AR grade In2O3were prepared by standard screen-printing technique. The gas sensing performances of thick films were tested for various gases. It showed maximum sensitivity to ethanol vapour at 350°C for 80 ppm concentration. To improve the sensitivity and selectivity of the film towards a particular gas, In2O3sensors were surface-modified by dipping them in a solution of 2% nanosilver for different intervals of time. Obtained results indicated that spherical nano-Ag grains are highly dispersed on the surface of In2O3sensor. The surface area of the nano-Ag/ In2O3sensor is several times larger than that of pure In2O3sensor. In comparison with pure In2O3sensor, all of the nano-Ag-doped sensors showed better sensing performance in respect of response, selectivity, and optimum operating temperature. The surface-modified (30 min) In2O3sensor showed larger sensitivity to H2S gas (10 ppm) at 100°C. Nano silver on the surface of the film shifts the reactivity of film from ethanol vapour to H2S gas. A systematic study of gas sensing performance of the sensor indicates the key role played by the nano silver species on the surface. The sensitivity, selectivity, response, and recovery time of the sensor were measured and presented.

Xylene-sensing of Fe2(MoO4)3 nanoplates prepared via a hydrothermal method

2017 ◽  
Vol 10 (03) ◽  
pp. 1750022 ◽  
Author(s):  
Mengying Xu ◽  
Zhidong Lin ◽  
Wenying Guo ◽  
Yuyuan Hong ◽  
Ping Fu ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Hydrothermal Process ◽  
Optimum Operating ◽  
Average Crystalline Size ◽  
Optimum Operating Temperature ◽  
Recovery Times ◽  
Response And Recovery ◽  
Simple Hydrothermal Process

Fe2(MoO4)3 nanoplates were prepared via a simple hydrothermal process. The average crystalline size of these nanoplates is 85.8[Formula: see text]nm. The sensor based on Fe2(MoO4)3 shows a high gas sensing performance to xylene. The response of Fe2(MoO4)3 sensor is 25.9–100[Formula: see text]ppm xylene at optimum operating temperature of 340[Formula: see text]C. The response and recovery times to 100[Formula: see text]ppm xylene are 4 and 10[Formula: see text]s, respectively. Furthermore, the Fe2(MoO4)3 sensor exhibits remarkable selectivity detection of xylene gas with negligible responses to toluene and benzene. Therefore, the Fe2(MoO4)3 is a promising material for the detection of xylene gas sensors.

SnO2 Nanofibers Gas Sensor Detecting H2 Dissolved in Transformer Oil

2013 ◽  
Vol 706-708 ◽  
pp. 1008-1011
Author(s):  
Shu Di Peng ◽  
Gao Lin Wu ◽  
Qian Wang
Keyword(s):  
Gas Sensor ◽  
Gas Sensing ◽  
Power Transformer ◽  
Synthesis Method ◽  
Transformer Oil ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Fault Gas ◽  
Response And Recovery ◽  
Hydrothermal Approach

Hydrogen is an effective fault gas dissolved in transformer oil, and online monitoring its concentration has important meaning on condition assessment and fault diagnosis of power transformer. A facile and simple synthesis method of ultra-sensitive SnO2nanofibers through a hydrothermal approach was reported. The crystalline phases and microstructures were performed by X-ray powder diffraction and field-emission scanning electron microscopy. The gas sensor based on prepared SnO2 nanofibers was fabricated by a side-heated preparation, and its gas sensing performances to H2were measured. The fabricated sensor exhibits excellent sensing properties to H2, such as low optimum operating temperature, high gas response, rapid response and recovery time, good stability and repeatability.

scholarly journals Ppb-Level Butanone Sensor Based on ZnO-TiO2-rGO Nanocomposites

Chemosensors ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 284
Author(s):  
Zhijia Liao ◽  
Yao Yu ◽  
Zhenyu Yuan ◽  
Fanli Meng
Keyword(s):  
Gas Sensing ◽  
Operating Temperature ◽  
Skin Irritation ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Lower Detection Limit ◽  
Gas Sensing Properties ◽  
Lower Detection ◽  
Organic Gases ◽  
Sensing Performance

In this paper, ZnO-TiO2-rGO nanocomposites were successfully synthesized by the hydrothermal method. The morphology and structure of the synthesized nanomaterials were characterized by SEM, XRD, HRTEM, and XPS. Butanone is a typical ketone product. The vapors are extremely harmful once exposed, triggering skin irritation in mild cases and affecting our breathing in severe cases. In this paper, the gas-sensing properties of TiO2, ZnO, ZnO-TiO2, and ZnO-TiO2-rGO nanomaterials to butanone vapor were studied. The optimum operating temperature of the ZnO-TiO2-rGO sensor is 145 °C, which is substantially lower than the other three sensors. The selectivity for butanone vapor is greatly improved, and the response is 5.6 times higher than that of other organic gases. The lower detection limit to butanone can reach 63 ppb. Therefore, the ZnO-TiO2-rGO sensor demonstrates excellent gas-sensing performance to butanone. Meanwhile, the gas-sensing mechanism of the ZnO-TiO2-rGO sensor to butanone vapor was also analyzed.

scholarly journals Enhanced Acetone Sensing Property of a Sacrificial Template Based on Cubic-Like MOF-5 Doped by Ni Nanoparticles

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 386 ◽  
Author(s):  
Ning Zhang ◽  
Huijun Li ◽  
Zhouqing Xu ◽  
Rui Yuan ◽  
Yongkun Xu ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Operating Temperature ◽  
Optimum Operating ◽  
Ni Nanoparticles ◽  
Optimum Operating Temperature ◽  
Structure And Morphology ◽  
Sensitivity And Selectivity ◽  
Loading Amount ◽  
Diabetes Monitoring ◽  
Acetone Sensor

Studying an acetone sensor with prominent sensitivity and selectivity is of great significance for the development of portable diabetes monitoring system. In this paper, cubic-like NiO/ZnO composites with different contents of Ni2+ were successfully synthesized by modifying MOF-5 with Ni2+-doped. The structure and morphology of the prepared composites were characterized by XRD, XPS, and SEM. The experimental results show that the NiO/ZnO composite showed an enhanced gas sensing property to acetone compared to pure ZnO, and the composites showed the maximum response value when Ni2+ loading amount was 5 at%. The response value of the 5% NiO/ZnO composite to acetone (500 ppm) at the optimum operating temperature (340 °C) is 7.3 times as that of pure ZnO. At the same time, the 5% NiO/ZnO composite has excellent selectivity and reproducibility for acetone. The gas sensing mechanism of the heterojunction sensor was described.

scholarly journals Nanostructured SmFeO3 Gas Sensors: Investigation of the Gas Sensing Performance Reproducibility for Colorectal Cancer Screening

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5910
Author(s):  
Andrea Gaiardo ◽  
Giulia Zonta ◽  
Sandro Gherardi ◽  
Cesare Malagù ◽  
Barbara Fabbri ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Gas Sensors ◽  
Process Development ◽  
Gas Sensing ◽  
Diagnostic Tools ◽  
Fecal Samples ◽  
Recovery Times ◽  
Medical Diagnostic ◽  
Response And Recovery ◽  
Sensing Performance

Among the various chemoresistive gas sensing properties studied so far, the sensing response reproducibility, i.e., the capability to reproduce a device with the same sensing performance, has been poorly investigated. However, the reproducibility of the gas sensing performance is of fundamental importance for the employment of these devices in on-field applications, and to demonstrate the reliability of the process development. This sensor property became crucial for the preparation of medical diagnostic tools, in which the use of specific chemoresistive gas sensors along with a dedicated algorithm can be used for screening diseases. In this work, the reproducibility of SmFeO3 perovskite-based gas sensors has been investigated. A set of four SmFeO3 devices, obtained from the same screen-printing deposition, have been tested in laboratory with both controlled concentrations of CO and biological fecal samples. The fecal samples tested were employed in the clinical validation protocol of a prototype for non-invasive colorectal cancer prescreening. Sensors showed a high reproducibility degree, with an error lower than 2% of the response value for the test with CO and lower than 6% for fecal samples. Finally, the reproducibility of the SmFeO3 sensor response and recovery times for fecal samples was also evaluated.

TUNGSTEN-DOPED TiO2 NANOLAYERS WITH IMPROVED CO2 GAS SENSING PROPERTIES FOR ENVIRONMENTAL APPLICATIONS

2017 ◽  
Vol 24 (Supp02) ◽  
pp. 1850024 ◽  
Author(s):  
MALIHEH SABERI ◽  
ALI AKBAR ASHKARRAN
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Sol Gel ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Sensing Properties ◽  
Vis Spectroscopy ◽  
Gas Sensing Properties ◽  
Tungsten Concentration

Tungsten-doped TiO2 gas sensors were successfully synthesized using sol–gel process and spin coating technique. The fabricated sensor was characterized by field emission scanning electron microscopy (FE-SEM), ultraviolet visible (UV–Vis) spectroscopy, transmission electron microscopy (TEM), X-Ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Gas sensing properties of pristine and tungsten-doped TiO2 nanolayers (NLs) were probed by detection of CO2 gas. A series of experiments were conducted in order to find the optimum operating temperature of the prepared sensors and also the optimum value of tungsten concentration in TiO2 matrix. It was found that introducing tungsten into the TiO2 matrix enhanced the gas sensing performance. The maximum response was found to be (1.37) for 0.001[Formula: see text]g tungsten-doped TiO2 NLs at 200[Formula: see text]C as an optimum operating temperature.

scholarly journals Enhanced Methane Sensing Properties of WO3 Nanosheets with Dominant Exposed (200) Facet via Loading of SnO2 Nanoparticles

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 351 ◽  
Author(s):  
Dongping Xue ◽  
Junjun Wang ◽  
Yan Wang ◽  
Guang Sun ◽  
Jianliang Cao ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Defect Density ◽  
Sno2 Nanoparticles ◽  
High Reactivity ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Sensing Properties ◽  
Long Term Stability ◽  
Subsequent Calcination

Methane detection is extremely difficult, especially at low temperatures, due to its high chemical stability. Here, WO3 nanosheets loaded with SnO2 nanoparticles with a particle size of about 2 nm were prepared by simple impregnation and subsequent calcination using SnO2 and WO3·H2O as precursors. The response of SnO2-loaded WO3 nanosheet composites to methane is about 1.4 times higher than that of pure WO3 at the low optimum operating temperature (90 °C). Satisfying repeatability and long-term stability are ensured. The dominant exposed (200) crystal plane of WO3 nanosheets has a good balance between easy oxygen chemisorption and high reactivity at the dangling bonds of W atoms, beneficial for gas-sensing properties. Moreover, the formation of a n–n type heterojunction at the SnO2-WO3 interface and additionally the increase of specific surface area and defect density via SnO2 loading enhance the response further. Therefore, the SnO2-WO3 composite is promising for the development of sensor devices to methane.

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