Defect-Controlled Gas Sensing Property of Nanostructured ZnO Films

2015 ◽  
Vol 814 ◽  
pp. 54-59
Author(s):  
Yong Qin Chang ◽  
Chang Jing Shao ◽  
Nan Jiang ◽  
Yan Jun Ma ◽  
Shi Qi Wang ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Oxygen Vacancies ◽  
Gas Sensing ◽  
Chemical Vapor ◽  
Zno Films ◽  
Sensor Applications ◽  
Cvd Method ◽  
Short Recovery Time ◽  
Gas Sensing Properties ◽  
Ethanol Sensing

Nanostructured ZnO films were fabricated by chemical vapor deposition (CVD) method with different Sn source concentrations for ethanol sensing application. It was found that the morphology of the ZnO films were obviously affected by Sn concentration, while no any Sn signals were detected in the films. The response of the nanostructured ZnO films increases with the increase of ethanol concentrations, and the S2 sample displays the highest sensitivity. Thephotoluminescence spectra show that more oxygen vacancies exist in the S2 sample than the other samples, which reveals that oxygen vacancies may play a great role to improve the gas sensing properties of the ZnO films.A possible sensing mechanism was proposed to explain these phenomena.This work provides a very simple and efficient method to prepare ZnO gas sensor, its high response and short recovery time are also a merit for the ZnO films used in gas sensor applications.

Oxygen vacancies-contained SnO2 nanotubes with enhanced ethanol gas sensing properties

2019 ◽  
Vol 34 (01n03) ◽  
pp. 2040003 ◽  
Author(s):  
Yifan Chen ◽  
Xiuling Ma ◽  
Chen Li ◽  
Qiuyu Wu ◽  
Yongbo Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Performance ◽  
Oxygen Vacancies ◽  
Gas Sensing ◽  
Original Sample ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Ethanol Sensing

[Formula: see text] porous nanotubes containing oxygen vacancies were prepared by electron spinning and H plasma treatment. The morphology and crystal structure of the samples were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The ethanol-sensing properties of the [Formula: see text] sensor were tested. The results show that the samples treated with H plasma for 20 min have the best performance. Its working temperature is [Formula: see text]C lower than [Formula: see text]C of the original sample, with a sensitivity of 17 at 100 ppm, which is seven times higher than the original sample. It also shows good selectivity to some common interfering gases. This enhancement can be ascribed to the introduced oxygen vacancy. This work provides an efficient way to design high-performance gas sensor materials.

Property of NOx Gas Sensor Using Carbon Nanotube Prepared by Thermal CVD Method

2007 ◽  
Vol 124-126 ◽  
pp. 1253-1256 ◽  
Author(s):  
Tsuyoshi Ueda ◽  
Md. Mosharaf Hossain Bhuiyan ◽  
H. Norimatsu ◽  
S. Katsuki ◽  
Tomoaki Ikegami
Keyword(s):  
Carbon Nanotube ◽  
Gas Sensor ◽  
Gas Sensing ◽  
Chemical Vapor ◽  
Gas Concentration ◽  
Thermal Cvd ◽  
Cvd Method ◽  
Pt Electrodes ◽  
Measured Resistance ◽  
Sensor Temperature

Carbon nanotube (CNT) gas sensors for NOx gas detection were prepared. CNTs were grown on an Al2O3 substrate with interdigital Pt-electrodes (Al2O3 ceramic substrate) using both pulsed laser deposition (PLD) and thermal chemical vapor deposition (CVD) method. In this method, Al buffer layer and Fe catalytic thin film were prepared on the substrate by PLD method and then CNTs were grown by thermal CVD method. Surface images of CNTs on the substrates were observed by SEM, and the gas sensing property specific to NO gas was measured. Resistance of the prepared CNTs gas sensor decreased with increase of sensor temperature, and it decreased with increase of NO gas concentration at room temperature.

Effect of Si substrate on ethanol gas sensing properties of ZnO films

2011 ◽  
Vol 519 (18) ◽  
pp. 6151-6154 ◽  
Author(s):  
Xiaoyan Zhou ◽  
Qingzhong Xue ◽  
Ming Ma ◽  
Jianpeng Li
Keyword(s):  
Gas Sensing ◽  
Zno Films ◽  
Si Substrate ◽  
Sensing Properties ◽  
Gas Sensing Properties

Star-Fruit-Shaped CuO Structures for High Performance Ethanol Gas Sensor Device

2021 ◽  
Vol 13 (4) ◽  
pp. 724-733
Author(s):  
Ahmad Umar ◽  
Ahmed A. Ibrahim ◽  
Rajesh Kumar ◽  
Hassan Algadi ◽  
Hasan Albargi ◽  
...  
Keyword(s):  
Gas Sensor ◽  
High Performance ◽  
Crystal Size ◽  
Gas Sensing ◽  
Sensor Applications ◽  
Sensor Device ◽  
Star Fruit ◽  
Micro Structures ◽  
Gas Response ◽  
Structural Crystal

In this paper, star-fruit-shaped CuO microstructures were hydrothermally synthesized and subsequently characterized through different techniques to understand morphological, compositional, structural, crystal, optical and vibrational properties. The formation of star-fruit-shaped structures along with some polygonal and spherical nanostructures was confirmed by FESEM analysis. XRD data and Raman spectrum confirmed the monoclinic tenorite crystalline phase of the CuO with crystal size 17.61 nm. Star-fruit-shaped CuO microstructures were examined for ethanol gas sensing behavior at various operating temperatures and concentrations. The gas response of 135% was observed at the optimal temperature of 225 °C. Due to excellent selectivity, stability and re-usability, the as-fabricated sensor based on star-fruit-shaped CuO micro-structures may be explored for future toxic gas sensor applications.

scholarly journals Preparation of Nanostructured SnO2-NiO Composite Semiconductor for Gas Sensor Applications

2021 ◽  
pp. 391-403
Author(s):  
S. Kumar ◽  
P. Gowthaman ◽  
J. Deenathayalan
Keyword(s):  
Gas Sensor ◽  
Composite Nanofibers ◽  
Volume Fraction ◽  
Gas Sensing ◽  
Precipitation Method ◽  
Response Sensitivity ◽  
X Ray ◽  
Sensing Properties ◽  
Working Temperature ◽  
Gas Sensing Properties

Electro spinning technology combined with chemical precipitation method and high-temperature calcination was used to prepare SnO2-NiO composite semiconductor nanofibers with different Sn content. Scanning electron microscope (SEM), X-ray diffractometer (XRD) and energy dispersive X-ray spectrometer (EDS) were used to characterize the morphology, structure and content of various elements of the sample. Using ethanol as the target gas, the gas sensing properties of SnO2-NiO nanofibers and the influence of Sn content on the gas sensing properties of composite nanofibers were explored. The research results show that SnO2-NiO composite nanofibers have a three-dimensional network structure, and the SnO2 composite can significantly enhance the gas sensitivity of NiO nanofibers. With increase of SnO2 content, the response sensitivity of composite fibers to ethanol gas increases, and the response sensitivity of composite nanofibers with the highest response to ethanol gas with a volume fraction of 100×10-6 at the optimal working temperature of 160℃ are13.4;It is 8.38 times the maximum response sensitivity of NiO nanofibers. Compared with the common ethanol gas sensor MQ-3 on the market, SnO2-NiO composite nanofibers have a lower optimal working temperature and higher response sensitivity, which has certain practical application value

scholarly journals Advanced Strategies to Improve Performances of Molybdenum-Based Gas Sensors

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Angga Hermawan ◽  
Ni Luh Wulan Septiani ◽  
Ardiansyah Taufik ◽  
Brian Yuliarto ◽  
Suyatman ◽  
...  
Keyword(s):  
High Performance ◽  
Gas Sensing ◽  
Low Cost ◽  
Molybdenum Oxides ◽  
Exhaled Breath ◽  
Sensor Applications ◽  
Theoretical Investigations ◽  
Gas Sensing Properties ◽  
Future Challenges ◽  
Made In

AbstractMolybdenum-based materials have been intensively investigated for high-performance gas sensor applications. Particularly, molybdenum oxides and dichalcogenides nanostructures have been widely examined due to their tunable structural and physicochemical properties that meet sensor requirements. These materials have good durability, are naturally abundant, low cost, and have facile preparation, allowing scalable fabrication to fulfill the growing demand of susceptible sensor devices. Significant advances have been made in recent decades to design and fabricate various molybdenum oxides- and dichalcogenides-based sensing materials, though it is still challenging to achieve high performances. Therefore, many experimental and theoretical investigations have been devoted to exploring suitable approaches which can significantly enhance their gas sensing properties. This review comprehensively examines recent advanced strategies to improve the nanostructured molybdenum-based material performance for detecting harmful pollutants, dangerous gases, or even exhaled breath monitoring. The summary and future challenges to advance their gas sensing performances will also be presented.

scholarly journals Chemically synthesized PbS Nano particulate thin films for a rapid NO2 gas sensor

2016 ◽  
Vol 34 (1) ◽  
pp. 204-211 ◽  
Author(s):  
Vishal V. Burungale ◽  
Rupesh S. Devan ◽  
Sachin A. Pawar ◽  
Namdev S. Harale ◽  
Vithoba L. Patil ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Sensor ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
Silar Method ◽  
Layer Adsorption ◽  
Gas Sensing Properties

AbstractRapid NO2 gas sensor has been developed based on PbS nanoparticulate thin films synthesized by Successive Ionic Layer Adsorption and Reaction (SILAR) method at different precursor concentrations. The structural and morphological properties were investigated by means of X-ray diffraction and field emission scanning electron microscope. NO2 gas sensing properties of PbS thin films deposited at different concentrations were tested. PbS film with 0.25 M precursor concentration showed the highest sensitivity. In order to optimize the operating temperature, the sensitivity of the sensor to 50 ppm NO2 gas was measured at different operating temperatures, from 50 to 200 °C. The gas sensitivity increased with an increase in operating temperature and achieved the maximum value at 150 °C, followed by a decrease in sensitivity with further increase of the operating temperature. The sensitivity was about 35 % for 50 ppm NO2 at 150 °C with rapid response time of 6 s. T90 and T10 recovery time was 97 s at this gas concentration.

A Novel Tungsten Trioxide Based Gas Sensor for Indoor Formaldehyde Detection

2021 ◽  
Vol 16 (3) ◽  
pp. 363-367
Author(s):  
Gaoqi Zhang ◽  
Fan Zhang ◽  
Kaifang Wang ◽  
Tao Tian ◽  
Shanyu Liu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Gas Sensor ◽  
Indoor Air ◽  
Gas Sensing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Material ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Gas Response

Accurate and real-time detection of formaldehyde (HCHO) in indoor air is urgently needed for human health. In this work, a ceramic material (WO3·H2O) with unique structure was successfully prepared using an efficient hydrothermal method. The crystallinity, morphology and microstructure of the as-prepared sensing material were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) as well as transmission electron microscope (TEM). The characterization results suggest that the as-prepared sample is composed of square-like nanoplates with uneven surface. Formaldehyde vapor is utilized as the target gas to investigate gas sensing properties of the synthesized novel nanoplates. The testing results indicate that the as-fabricated gas sensor exhibit high gas response and excellent repeatability to HCHO gas. The response value (Ra/Rg) is 24.5 towards 70 ppm HCHO gas at 350 °C. Besides, the gas sensing mechanism was described.

UV enhanced NO gas sensing properties of the MoS2 monolayer gas sensor

2019 ◽  
Vol 6 (8) ◽  
pp. 085075 ◽  
Author(s):  
S Ramu ◽  
T Chandrakalavathi ◽  
G Murali ◽  
K Sunil Kumar ◽  
A Sudharani ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Gas Sensing ◽  
Sensing Properties ◽  
Mos2 Monolayer ◽  
Gas Sensing Properties

Excellent Gas Sensing of CdS Nanowires Decorated with Ag Nanoparticles

2019 ◽  
Vol 19 (11) ◽  
pp. 7083-7088 ◽  
Author(s):  
Nan Zhang ◽  
Xiaohui Ma ◽  
Shengping Ruan ◽  
Yanyang Yin ◽  
Chuannan Li ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Ag Nanoparticles ◽  
Gas Sensing ◽  
Average Diameter ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Cds Nanowires ◽  
The Stability ◽  
Ethanol Sensing ◽  
The One

In this study, CdS nanowires (NWs)/Ag nanoparticle materials (CdS@Ag) with Schottky junction were synthesized by a simple process. The Ag nanoparticles with a diameter of 3–10 nm were uniformly scattered on the surface of CdS NWs with an average diameter of 30 nm. The gas sensing properties and the effect of Ag content and relative humidity on the ethanol sensing properties of CdS NWs were investigated in detail. When the relative humidity was below 60% RH, the sensor, especially the one based on [email protected], exhibited an enhanced ethanol sensing response and selectivity compared with that of pristine CdS NWs, which was believed that Ag catalyzed the reaction between ionized oxygen species and ethanol. However, excessive Ag content does not mean a higher response and even decreased the response. Also, the stability of CdS NWs and CdS@Ag NWs was also investigated, which were almost stable for four months.

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