scholarly journals Preparation of Flower-Like Cu-WO3Nanostructures and Their Acetone Gas Sensing Performance

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Hao Zhou ◽  
Dong-Yao Xu ◽  
Hai-Qing Zuo ◽  
Wei Liu ◽  
Shuang Lin
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Hydrothermal Process ◽  
High Sensitivity ◽  
Test System ◽  
Static State ◽  
Acetone Concentration ◽  
Detection Range ◽  
Gas Sensing Properties ◽  
Linear Fit

Urchin-like Cu-W18O49and flower-like Cu-WO3structures were successfully synthesized using a hydrothermal process followed by calcination. The synthesized products were characterized using XRD, SEM, and TEM. The results revealed that the as-prepared urchin-like and flower-like samples with monoclinic structures, which were approximately 1 μm and 1-2 μm, respectively, possessed microflower architecture assembled by the nanosheet. In addition, the gas sensing properties of monoclinic-structured Cu-WO3to acetone were measured using a static state gas sensing test system. The sensor based on the flower-like Cu-WO3nanostructures, which were calcined at 600°C, exhibited high sensitivity toward 10 ppm acetone at an optimum temperature of 110°C, and the maximum sensitivity reached 40, which was approximately four times higher than that of urchin-like WO3that was annealed at 300°C. The sensitivity was improved by increasing the acetone concentration. The detection limit was as low as 1 ppm. Using linear fit, the sensor was determined to be sufficiently sensitive to detect acetone in a detection range of 1 to 10 ppm even in the presence of interfering gases, which suggests that this type of sensor has excellent selectivity and has the potential for use in acetone gas sensors in the future.

scholarly journals Discriminable Sensing Response Behavior to Homogeneous Gases Based on n-ZnO/p-NiO Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 785 ◽  
Author(s):  
Wen-Dong Zhou ◽  
Davoud Dastan ◽  
Jing Li ◽  
Xi-Tao Yin ◽  
Qi Wang
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Sol Gel ◽  
High Sensitivity ◽  
Oxide Semiconductor ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
P Type ◽  
Type Response ◽  
Properties Of Composites

Metal oxide semiconductor (MOS) gas sensors have the advantages of high sensitivity, short response-recovery time and long-term stability. However, the shortcoming of poor discriminability of homogeneous gases limits their applications in gas sensors. It is well-known that the MOS materials have similar gas sensing responses to homogeneous gases such as CO and H2, so it is difficult for these gas sensors to distinguish the two gases. In this paper, simple sol–gel method was employed to obtain the ZnO–xNiO composites. Gas sensing performance results illustrated that the gas sensing properties of composites with x > 0.425 showed a p-type response to both CO and H2, while the gas sensing properties of composites with x < 0.425 showed an n-type response to both CO and H2. However, it was interesting that ZnO–0.425NiO showed a p-type response to CO but an discriminable response (n-type) to H2, which indicated that modulating the p-type or n-type semiconductor concentration in p-n composites could be an effective method with which to improve the discriminability of this type of gas sensor regarding CO and H2. The phenomenon of the special gas sensing behavior of ZnO–0.425NiO was explained based on the experimental observations and a range of characterization techniques, including XRD, HRTEM and XPS, in detail.

NOx Gas Sensing Properties of Fe-Doped ZnO Nanoparticles

2020 ◽  
Vol 12 (6) ◽  
pp. 908-914 ◽  
Author(s):  
Ahmad Umar ◽  
M. Alduraibi ◽  
Omar Al-Dossary
Keyword(s):  
Gas Sensors ◽  
Zno Nanoparticles ◽  
Gas Sensing ◽  
Hydrothermal Process ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Different Temperatures ◽  
Response And Recovery ◽  
Doped Zno ◽  
Gas Response

Herein, NOx, i.e., nitric oxide (NO) and nitrogen dioxide (NO2), gas sensors were fabricated using iron (Fe)-doped ZnO nanoparticles prepared via the facile hydrothermal process. The synthesized Fe-doped ZnO nanoparticles were analyzed through several techniques that revealed the well-crystallinity and dense growth of nanoparticles with the typical diameters of 25 ± 5 nm. The synthesized nanoparticles were utilized as a prospective material for the fabrication of NOx gas sensors operating at different temperatures, i.e., 350 °C, 400 °C, and 450 °C. The detailed sensing performances revealed that the optimum and most suitable sensing temperature for the fabricated sensors is 400 °C. In presence of 10 ppm NO gas, the fabricated sensor exhibited the highest gas response of 1.35 with a response (tresponse) and recovery (trecovery) time of 44 s and 402 s, respectively. Similarly, the fabricated NO2 gas sensor, in presence of 10 ppm gas shows the highest gas response of 1.33 with a response and recovery times of 50 s and 281 s, respectively. The presented results demonstrate that Fe-doped ZnO nanomaterials are capable to fabricate efficient NOx gas sensors.

V2O5 Nanotubes Novel Gas Sensor with High Sensitivity for Ethanol

2009 ◽  
Vol 421-422 ◽  
pp. 328-331 ◽  
Author(s):  
Wei Jin ◽  
Wen Chen ◽  
Bai Tao Dong ◽  
Chun Xia Zhao ◽  
Li Qiang Mai ◽  
...  
Keyword(s):  
Vanadium Oxide ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Gas Sensing ◽  
Hydrothermal Reaction ◽  
High Sensitivity ◽  
Average Diameter ◽  
Self Assembling ◽  
Gas Sensing Properties ◽  
Vanadium Oxide Nanotubes

Vanadium oxide nanotubes were synthesized via a rheological self-assembling process followed by a hydrothermal reaction. V2O5 gas sensors were fabricated from vanadium oxide nanotubess with an average diameter of around 90 nm and their gas-sensing properties were investigated. It was found that the sensors based on vanadium oxide nanotubes exhibit high responses ethanol gas at 270°C. The results indicate that vanadium oxide nanotube sensors will be promising candidates for practical detectors for ethanol.

scholarly journals Improving Gas-Sensing Performance Based on MOS Nanomaterials: A Review

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4263
Author(s):  
Shirui Xue ◽  
Sicheng Cao ◽  
Zhaoling Huang ◽  
Daoguo Yang ◽  
Guoqi Zhang
Keyword(s):  
Gas Sensors ◽  
Agricultural Production ◽  
Gas Adsorption ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Oxide Semiconductor ◽  
Sensing Properties ◽  
Advantages And Disadvantages ◽  
Short Recovery Time ◽  
Gas Sensing Properties

In order to solve issues of air pollution, to monitor human health, and to promote agricultural production, gas sensors have been used widely. Metal oxide semiconductor (MOS) gas sensors have become an important area of research in the field of gas sensing due to their high sensitivity, quick response time, and short recovery time for NO2, CO2, acetone, etc. In our article, we mainly focus on the gas-sensing properties of MOS gas sensors and summarize the methods that are based on the interface effect of MOS materials and micro–nanostructures to improve their performance. These methods include noble metal modification, doping, and core-shell (C-S) nanostructure. Moreover, we also describe the mechanism of these methods to analyze the advantages and disadvantages of energy barrier modulation and electron transfer for gas adsorption. Finally, we put forward a variety of research ideas based on the above methods to improve the gas-sensing properties. Some perspectives for the development of MOS gas sensors are also discussed.

Schottky diodes based on 2D materials for environmental gas monitoring: a review on emerging trends, recent developments and future perspectives

2021 ◽  
Author(s):  
Minu Mathew ◽  
Chandra Sekhar Rout
Keyword(s):  
Gas Sensing ◽  
2D Materials ◽  
Schottky Diodes ◽  
High Sensitivity ◽  
Future Perspectives ◽  
Working Temperature ◽  
Emerging Trends ◽  
Gas Sensing Properties ◽  
Recent Developments ◽  
Sensitivity And Selectivity

This review details the fundamentals, working principles and recent developments of Schottky junctions based on 2D materials to emphasize their improved gas sensing properties including low working temperature, high sensitivity, and selectivity.

scholarly journals Enhancing Formaldehyde Selectivity of SnO2 Gas Sensors with the ZSM-5 Modified Layers

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3947
Author(s):  
Wei Wang ◽  
Qinyi Zhang ◽  
Ruonan Lv ◽  
Dong Wu ◽  
Shunping Zhang
Keyword(s):  
Gas Sensors ◽  
Indoor Air ◽  
High Performance ◽  
Screen Printing ◽  
Gas Sensing ◽  
Oxide Semiconductors ◽  
Screen Printing Method ◽  
Gas Sensing Properties ◽  
Zeolite Films ◽  
Insufficient Knowledge

High performance formaldehyde gas sensors are widely needed for indoor air quality monitoring. A modified layer of zeolite on the surface of metal oxide semiconductors results in selectivity improvement to formaldehyde as gas sensors. However, there is insufficient knowledge on how the thickness of the zeolite layer affects the gas sensing properties. In this paper, ZSM-5 zeolite films were coated on the surface of the SnO2 gas sensors by the screen printing method. The thickness of ZSM-5 zeolite films was controlled by adjusting the numbers of screen printing layers. The influence of ZSM-5 film thickness on the performance of ZSM-5/SnO2 gas sensors was studied. The results showed that the ZSM-5/SnO2 gas sensors with a thickness of 19.5 μm greatly improved the selectivity to formaldehyde, and reduced the response to ethanol, acetone and benzene at 350 °C. The mechanism of the selectivity improvement to formaldehyde of the sensors was discussed.

Polyaniline/SnO2 Nanocomposite Sensor for NO2 Gas Sensing at Low Operating Temperature

2015 ◽  
Vol 14 (04) ◽  
pp. 1550011 ◽  
Author(s):  
A. Sharma ◽  
M. Tomar ◽  
V. Gupta ◽  
A. Badola ◽  
N. Goswami
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
Sensing Properties ◽  
Response Recovery ◽  
Transmission Electron ◽  
Gas Sensing Properties

In this paper gas sensing properties of 0.5–3% polyaniline (PAni) doped SnO 2 thin films sensors prepared by chemical route have been studied towards the trace level detection of NO 2 gas. The structural, optical and surface morphological properties of the PAni doped SnO 2 thin films were investigated by performing X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Raman spectroscopy measurements. A good correlation has been identified between the microstructural and gas sensing properties of these prepared sensors. Out of these films, 1% PAni doped SnO 2 sensor showed high sensitivity towards NO 2 gas along with a sensitivity of 3.01 × 102 at 40°C for 10 ppm of gas. On exposure to NO 2 gas, resistance of all sensors increased to a large extent, even greater than three orders of magnitude. These changes in resistance upon removal of NO 2 gas are found to be reversible in nature and the prepared composite film sensors showed good sensitivity with relatively faster response/recovery speeds.

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.

Preparation and Gas-Sensing Property of Coppertetra-Iso-Propoxyphthalocyanine Spin-Coating Film

2011 ◽  
Vol 197-198 ◽  
pp. 1735-1738
Author(s):  
Qiang Li ◽  
Li Hua Huo ◽  
Shan Gao ◽  
Xiao Juan Qi ◽  
Hui Zhao
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Coating Film ◽  
Gas Sensing Properties ◽  
Response And Recovery ◽  
Ft Ir ◽  
Spinning Speed ◽  
Spectroscopy Property

The thin films of copper 2, 9, 16, 23-tetra-iso-propoxy phthalocyanine (i-pro-CuPc) were prepared by spin-coating technique. The surface morphology and spectroscopy property of the thin films were characterized by AFM, UV-Vis and FT-IR spectra. The results show that good films can be obtained under certain spinning speed. The gas-sensing properties of the multilayers to three alcohols gas were measured at room temperature. The spin-coating thin films exhibited high sensitivity and rapid response- recovery characteristics to these gases. The response and recovery time of the thin films to 30*10-6 v/v of C2H5OH vapor is only 28 s and 55 s, respectively.

The effect of Nb doping on hydrogen gas sensing properties of capacitor-like Pt/Nb-TiO2/Pt hydrogen gas sensors

2019 ◽  
Vol 806 ◽  
pp. 1052-1059 ◽  
Author(s):  
Zhong Li ◽  
ZhengJun Yao ◽  
Azhar Ali Haidry ◽  
Tomas Plecenik ◽  
Branislav Grancic ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Hydrogen Gas ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Hydrogen Gas Sensors ◽  
Nb Doping
Sign in / Sign up

Export Citation Format

Share Document