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

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.

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 785 ◽  
Author(s):  
Wen-Dong Zhou ◽  
Davoud Dastan ◽  
Jing Li ◽  
Xi-Tao Yin ◽  
Qi Wang

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.


2015 ◽  
Vol 14 (04) ◽  
pp. 1550011 ◽  
Author(s):  
A. Sharma ◽  
M. Tomar ◽  
V. Gupta ◽  
A. Badola ◽  
N. Goswami

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.


2019 ◽  
Vol 806 ◽  
pp. 1052-1059 ◽  
Author(s):  
Zhong Li ◽  
ZhengJun Yao ◽  
Azhar Ali Haidry ◽  
Tomas Plecenik ◽  
Branislav Grancic ◽  
...  

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3323 ◽  
Author(s):  
Jae-Hyoung Lee ◽  
Thanh-Binh Nguyen ◽  
Duy-Khoi Nguyen ◽  
Jae-Hun Kim ◽  
Jin-Young Kim ◽  
...  

The gas sensing properties of two novel series of Mg-incorporated metal–organic frameworks (MOFs), termed Mg-MOFs-I and -II, were assessed. The synthesized iso-reticular type Mg-MOFs exhibited good crystallinity, high thermal stability, needle-shape morphology and high surface area (up to 2900 m2·g−1), which are promising for gas sensing applications. Gas-sensing studies of gas sensors fabricated from Mg-MOFs-II revealed better sensing performance, in terms of the sensor dynamics and sensor response, at an optimal operating temperature of 200 °C. The MOF gas sensor with a larger pore size and volume showed shorter response and recovery times, demonstrating the importance of the pore size and volume on the kinetic properties of MOF-based gas sensors. The gas-sensing results obtained in this study highlight the potential of Mg-MOFs gas sensors for the practical monitoring of toxic gases in a range of environments.


1999 ◽  
Vol 119 (2) ◽  
pp. 103-107 ◽  
Author(s):  
Takeo Hyodo ◽  
Keiko Okamoto ◽  
Yuji Takao ◽  
Yasuhiro Shimizu ◽  
Makoto Egashira

2020 ◽  
Vol MA2020-01 (28) ◽  
pp. 2114-2114
Author(s):  
Mykhailo Vorokhta ◽  
Pavel Hozak ◽  
Ivan Khalakhan ◽  
Martin Vrnata ◽  
Ján Lančok ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Hao Zhou ◽  
Dong-Yao Xu ◽  
Hai-Qing Zuo ◽  
Wei Liu ◽  
Shuang Lin

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.


2006 ◽  
Vol 915 ◽  
Author(s):  
Roberto Mosca ◽  
Mingzheng Zha ◽  
Davide Calestani ◽  
Laura Lazzarini ◽  
Giancarlo Salviati ◽  
...  

AbstractSnO2 nanowires have been recently employed in the “gas-sensors” field and excellent results of conductometric and optical tests on SnO2 nanowires-based gas sensors have been reported.However, the mechanism that controls the gas-sensing effect in metal oxides nanowires is not fully understood yet. Here the authors present the first results of an in-depth study about the influence of post growth treatments on the physical and gas sensing properties of SnO2 nanowires.In particular, SnO2 nanowires grown by a vapour transport technique were annealed in a oxygen-rich atmosphere and then characterized by different techniques to assess the influence of the treatment on the nanowires properties.The annealing in oxygen atmosphere is shown to strongly affect the PL and CL spectra, the electrical resistivity as well as the gas sensing properties of the nanowires. The obtained results are consistent with a reduction of the oxygen vacancies concentration induced by the O2 treatment and seem to confirm the role of these defects in affecting the gas response of SnO2 nanowires-based sensors.


RSC Advances ◽  
2014 ◽  
Vol 4 (90) ◽  
pp. 49521-49528 ◽  
Author(s):  
Mohammad R. Alenezi ◽  
T. H. Alzanki ◽  
A. M. Almeshal ◽  
A. S. Alshammari ◽  
M. J. Beliatis ◽  
...  

Enhanced gas sensing properties of ZnO were achieved by designing hierarchical nanostructures with high surface-to-volume ratios and more exposed polar facets.


Sign in / Sign up

Export Citation Format

Share Document