ZnO-SnO2 nanocomposites modified by PdO nanoparticles named PdO-ZSO as gas sensing material for hydrogen and butane with the excellent response time and recovery time

Author(s):  
Guangdi Liu ◽  
Xiuxiu Cui ◽  
Lijia Yao ◽  
Rongjun Zhao ◽  
Xu Tian ◽  
...  
Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1708
Author(s):  
Ruochen Peng ◽  
Qu Zhou ◽  
Wen Zeng

As an insulating medium, sulfur hexafluoride (SF6) is extensively applied to electrical insulation equipment to ensure its normal operation. However, both partial discharge and overheating may cause SF6 to decompose, and then the insulation strength of electrical equipment will be reduced. The adsorption properties and sensing mechanisms of four SF6 decomposed components (HF, SO2, SOF2 and SO2F2) upon an Au-modified InN (Au-InN) monolayer were studied in this work based on first-principles theory. Meanwhile, the adsorption energy (Ead), charge transfer (QT), deformation charge density (DCD), density of states (DOS), frontier molecular orbital and recovery property were calculated. It can be observed that the structures of the SO2, SOF2 and SO2F2 molecules changed significantly after being adsorbed. Meanwhile, the Ead and QT of these three adsorption systems are relatively large, while that of the HF adsorption system is the opposite. These phenomena indicate that Au-InN monolayer has strong adsorption capacity for SO2, SOF2 and SO2F2, and the adsorption can be identified as chemisorption. In addition, through the analysis of frontier molecular orbital, it is found that the conductivity of Au-InN changed significantly after adsorbing SO2, SOF2 and SO2F2. Combined with the analysis of the recovery properties, since the recovery time of SO2 and SO2F2 removal from Au-InN monolayer is still very long at 418 K, Au-InN is more suitable as a scavenger for these two gases rather than as a gas sensor. Since the recovery time of the SOF2 adsorption system is short at 418 K, and the conductivity of the system before and after adsorption changes significantly, Au-InN is an ideal SOF2 gas-sensing material. These results show that Au-InN has broad application prospects as an SO2, SOF2 and SO2F2 scavenger and as a resistive SOF2 sensor, which is of extraordinary meaning to ensure the safe operation of power systems. Our calculations can offer a theoretical basis for further exploration of gas adsorbent and resistive sensors prepared by Au-InN.


2010 ◽  
Vol 148-149 ◽  
pp. 1042-1046
Author(s):  
Jin Yang Lin ◽  
Yong Ai Zhang ◽  
Ling Jie Wang ◽  
Tai Liang Guo

Novel tungsten oxide sensors were fabricated based on Hall Effect and their NO2 gas sensing properties were examined. Tungsten trioxide was grown by vapor evaporation of metal tungsten filament in an oxygen atmosphere. A WO3 thick film was deposited on the four Au electrode to be a WO3 sensor. The sensor was tested between magnetic field in a plastic test chamber. The gas sensing experiment revealed that at the NO2 concentration of 40 ppm, a sensitivity of 3.27, a response time of 36 s, and a recovery time of 45 s were observed at room-temperature. The effect of WO3 based on Hall Effect on the sensing characteristic is discussed.


2020 ◽  
Vol 7 (6) ◽  
pp. 1474-1482 ◽  
Author(s):  
Dongxue Wang ◽  
Chengbo Zhai ◽  
Liyong Du ◽  
Kuikun Gu ◽  
Mingzhe Zhang

The response of our Fe-doped NiO TEA sensor was about 21 times higher than that of the pure sensor. The quick response time and recovery time, good selectivity and stability, and enhanced gas sensing properties could be attributed to Fe-doping.


2011 ◽  
Vol 399-401 ◽  
pp. 727-730
Author(s):  
Yue Huan Li ◽  
Yong Jun Liu ◽  
Xue Chun Xiao ◽  
Hu En Kan ◽  
He Yun Zhao

SnO2nanorods with rutile structure were successfully synthesized by solid state reaction in the presence of NaCl-KCl. Indirect-heating sensors based on nanorods were fabricated and investigated for the gas sensing properties to ethanol. The results showed that the response of sensor to 1000 ppm ethanol is up to 114.3, the export voltage to 1 ppm ethanol can attain 2.0 V at 275 °C, and the response time and recovery time are no longer than 10 s.


2021 ◽  
Vol 3 (3) ◽  
Author(s):  
P. R. Godse ◽  
A. T. Mane ◽  
Y. H. Navale ◽  
S. T. Navale ◽  
R. N. Mulik ◽  
...  

AbstractThe present paper reports novel approach of surfactant and template free aqueous hydrothermal growth of 1D ZnO nanostructures, which facilitates the generation of large scale, low cost, and moderate working temperature films with controlled morphology for NO2 gas sensor application. Gas sensing properties of 1D ZnO nanostructures were studied at various temperatures for different reducing and oxidizing gases. As-fabricated by 1D ZnO nanostructures showed the highest sensor response of 11,791% with rapid response time of 9 s and recovery time of 220 s towards 100 ppm NO2. Moreover, for 5 ppm NO2 concentration, sensor showed a significant response of 70% with an response time of 16 s and recovery time of 200 s. The sensor shows good continuous performance in terms of response, response time, and recovery time, indicating that the sensor is highly reproducible and stable as well. This study successfully employed 1D ZnO nanostructures based NO2 sensing within the higher (100 ppm) and lower exposure limit (5 ppm) of NO2 gas.


2019 ◽  
Vol 17 (40) ◽  
pp. 21-32
Author(s):  
Iftikhar M. Ali

The pure ZnS and ZnS-Gr nanocomposite have been preparedsuccessfully by a novel method using chemical co-precipitation. Alsoconductive polymer PPy nanotubes and ZnS-PPy nanocompositehave been synthesized successfully by chemical route. The effect ofgraphene on the characterization of ZnS has been investigated. X-raydiffraction (XRD) study confirmed the formation of cubic andhexagonal structure of ZnS-Gr. Dc-conductivity proves that ZnS andZnS-Gr have semiconductor behavior. The SEM proved thatformation of PPy nanotubes and the Gr nanosheet. The sensingproperties of ZnS-PPy/ZnS-Gr for NO2 gas was investigated as afunction of operating temperature and time under optimal condition.The sensitivity, response time and recovery time were calculatedwith different operating temperatures.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 783 ◽  
Author(s):  
Andrea Gaiardo ◽  
David Novel ◽  
Elia Scattolo ◽  
Michele Crivellari ◽  
Antonino Picciotto ◽  
...  

The substrate plays a key role in chemoresistive gas sensors. It acts as mechanical support for the sensing material, hosts the heating element and, also, aids the sensing material in signal transduction. In recent years, a significant improvement in the substrate production process has been achieved, thanks to the advances in micro- and nanofabrication for micro-electro-mechanical system (MEMS) technologies. In addition, the use of innovative materials and smaller low-power consumption silicon microheaters led to the development of high-performance gas sensors. Various heater layouts were investigated to optimize the temperature distribution on the membrane, and a suspended membrane configuration was exploited to avoid heat loss by conduction through the silicon bulk. However, there is a lack of comprehensive studies focused on predictive models for the optimization of the thermal and mechanical properties of a microheater. In this work, three microheater layouts in three membrane sizes were developed using the microfabrication process. The performance of these devices was evaluated to predict their thermal and mechanical behaviors by using both experimental and theoretical approaches. Finally, a statistical method was employed to cross-correlate the thermal predictive model and the mechanical failure analysis, aiming at microheater design optimization for gas-sensing applications.


2021 ◽  
Vol 11 (15) ◽  
pp. 6675
Author(s):  
Tran Si Trong Khanh ◽  
Tran Quang Trung ◽  
Le Thuy Thanh Giang ◽  
Tran Quang Nguyen ◽  
Nguyen Dinh Lam ◽  
...  

In this work, the P3HT:rGO:MWCNTs (PGC) nanocomposite film applied to the ammonia gas sensor was successfully fabricated by a drop-casting technique. The results demonstrated that the optimum weight ratio of the PGC nanocomposite gas sensor is 20%:60%:20% as the weight ratio of P3HT:rGO:MWCNTs (called PGC-60). This weight ratio leads to the formation of nanostructured composites, causing the efficient adsorption/desorption of ammonia gas in/out of the film surface. The sensor based on PGC-60 possessed a response time of 30 s, sensitivity up to 3.6% at ammonia gas concentration of 10 ppm, and relative sensitivity of 0.031%/ppm. These results could be attributed to excellent electron transportation of rGO, the main adsorption activator to NH3 gas of P3HT, and holes move from P3HT to the cathodes, which works as charge “nano-bridges” carriers of Multi-Walled Carbon Nanotubes (MWCNTs). In general, these three components of PGC sensors have significantly contributed to the improvement of both the sensitivity and response time in the NH3 gas sensor.


Author(s):  
Ravi Shankar ◽  
Tien Choy Loh ◽  
Le Khaing Le ◽  
Chun Wei Khor ◽  
Shian Yeu Kam ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (104) ◽  
pp. 102264-102271 ◽  
Author(s):  
Sanjeev K. Gupta ◽  
Deobrat Singh ◽  
Kaptansinh Rajput ◽  
Yogesh Sonvane

The structural stability and electronic properties of the adsorption characteristics of several toxic gas molecules (NH3, SO2 and NO2) on a germanene monolayer were investigated using density functional theory (DFT) based on an ab initio method.


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