scholarly journals Highly Sensitive, Selective, Flexible and Scalable Room-Temperature NO2 Gas Sensor Based on Hollow SnO2/ZnO Nanofibers

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6475
Author(s):  
Jiahui Guo ◽  
Weiwei Li ◽  
Xuanliang Zhao ◽  
Haowen Hu ◽  
Min Wang ◽  
...  

Semiconducting metal oxides can detect low concentrations of NO2 and other toxic gases, which have been widely investigated in the field of gas sensors. However, most studies on the gas sensing properties of these materials are carried out at high temperatures. In this work, Hollow SnO2 nanofibers were successfully synthesized by electrospinning and calcination, followed by surface modification using ZnO to improve the sensitivity of the SnO2 nanofibers sensor to NO2 gas. The gas sensing behavior of SnO2/ZnO sensors was then investigated at room temperature (~20 °C). The results showed that SnO2/ZnO nanocomposites exhibited high sensitivity and selectivity to 0.5 ppm of NO2 gas with a response value of 336%, which was much higher than that of pure SnO2 (13%). In addition to the increase in the specific surface area of SnO2/ZnO-3 compared with pure SnO2, it also had a positive impact on the detection sensitivity. This increase was attributed to the heterojunction effect and the selective NO2 physisorption sensing mechanism of SnO2/ZnO nanocomposites. In addition, patterned electrodes of silver paste were printed on different flexible substrates, such as paper, polyethylene terephthalate and polydimethylsiloxane using a facile screen-printing process. Silver electrodes were integrated with SnO2/ZnO into a flexible wearable sensor array, which could detect 0.1 ppm NO2 gas after 10,000 bending cycles. The findings of this study therefore open a general approach for the fabrication of flexible devices for gas detection applications.

2019 ◽  
Vol 1 (5) ◽  
pp. 2009-2017 ◽  
Author(s):  
E. Petromichelaki ◽  
E. Gagaoudakis ◽  
K. Moschovis ◽  
L. Tsetseris ◽  
T. D. Anthopoulos ◽  
...  

The fundamental development of the design of novel self-powered ozone sensing elements, operating at room temperature, based on p-type metal oxides paves the way to a new class of low cost, highly promising gas sensing devices.


2007 ◽  
Vol 7 (12) ◽  
pp. 4439-4442 ◽  
Author(s):  
Chuanwei Cheng ◽  
Guoyue Xu ◽  
Haiqian Zhang ◽  
Yan Luo

We present a sensor fabricated by simply casting ZnO nanorods on a microelectrodes array for chemical gas detection at room temperature. The ammonia and ethanol gas sensing characteristics were carefully investigated. The sensor exhibited high sensitivity for both ammonia and ethanol gases. The response and recover time are less than 20 seconds, respectively. Present results demonstrate the potential application of ZnO nanorods for fabricating highly sensitive gas sensors.


Author(s):  
Minu Mathew ◽  
Chandra Sekhar Rout

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.


Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3815
Author(s):  
Renyun Zhang ◽  
Magnus Hummelgård ◽  
Joel Ljunggren ◽  
Håkan Olin

Metal-semiconductor junctions and interfaces have been studied for many years due to their importance in applications such as semiconductor electronics and solar cells. However, semiconductor-metal networks are less studied because there is a lack of effective methods to fabricate such structures. Here, we report a novel Au–ZnO-based metal-semiconductor (M-S)n network in which ZnO nanowires were grown horizontally on gold particles and extended to reach the neighboring particles, forming an (M-S)n network. The (M-S)n network was further used as a gas sensor for sensing ethanol and acetone gases. The results show that the (M-S)n network is sensitive to ethanol (28.1 ppm) and acetone (22.3 ppm) gases and has the capacity to recognize the two gases based on differences in the saturation time. This study provides a method for producing a new type of metal-semiconductor network structure and demonstrates its application in gas sensing.


2017 ◽  
Vol 5 (38) ◽  
pp. 9943-9951 ◽  
Author(s):  
Xubin Zheng ◽  
Ruiqing Fan ◽  
Yang Song ◽  
Ani Wang ◽  
Kai Xing ◽  
...  

A novel probe, designed and prepared through PSM of Cu-MOFs and Tb3+ions, shows high sensitivity and selectivity for H2S.


RSC Advances ◽  
2015 ◽  
Vol 5 (92) ◽  
pp. 75098-75104 ◽  
Author(s):  
Xinghua Chang ◽  
Mi Peng ◽  
Junfeng Yang ◽  
Teng Wang ◽  
Yu liu ◽  
...  

A light activated miniature formaldehyde sensor working at room temperature is fabricated by CdSO4 modified ZnO nanoparticles.


Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 626
Author(s):  
Seokhun Kwon ◽  
Seokwon Lee ◽  
Joouk Kim ◽  
Chulmin Park ◽  
Hosung Jung ◽  
...  

Recently, as air pollution and particulate matter worsen, the importance of a platform that can monitor the air environment is emerging. Especially, among air pollutants, nitrogen dioxide (NO2) is a toxic gas that can not only generate secondary particulate matter, but can also derive numerous toxic gases. To detect such NO2 gas at low concentration, we fabricated a GNWs/NiO-WO3/GNWs heterostructure-based gas sensor using microwave plasma-enhanced chemical vapor deposition (MPECVD) and sputter, and we confirmed the NO2 detection characteristics between 10 and 50 ppm at room temperature. The morphology and carbon lattice characteristics of the sensing layer were investigated using field emission scanning electron microscopy (FESEM) and Raman spectroscopy. In the gas detection measurement, the resistance negative change according to the NO2 gas concentration was recorded. Moreover, it reacted even at low concentrations such as 5–7 ppm, and showed excellent recovery characteristics of more than 98%. Furthermore, it also showed a change in which the reactivity decreased with respect to humidity of 33% and 66%.


Author(s):  
Monika Kwoka ◽  
Michal A. Borysiewicz ◽  
Pawel Tomkiewicz ◽  
Anna Piotrowska ◽  
Jacek Szuber

In this paper a novel type of a highly sensitive gas sensor device based on the surface photovoltage effect is described. The developed surface photovoltage gas sensor is based on a reverse Kelvin probe approach. As the active gas sensing electrode the porous ZnO nanostructured thin films are used deposited by the direct current (DC) reactive magnetron sputtering method exhibiting the nanocoral surface morphology combined with an evident surface nonstoichiometry related to the unintentional surface carbon and water vapor contaminations. Among others, the demonstrated SPV gas sensor device exhibits a high sensitivity of 1 ppm to NO2 with a signal to noise ratio of about 50 and a fast response time of several seconds under the room temperature conditions.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Yang Qiao ◽  
Zeqi Li ◽  
Mei-Hui Yu ◽  
Ze Chang ◽  
Xian-He Bu

High sensitivity and selectivity for detection of metal ions are very important to protect human health. Fluorescent metal-organic framework (MOF) as a new sensing material has attracted more and more...


2020 ◽  
Vol 44 (44) ◽  
pp. 19155-19165
Author(s):  
Burcu Aydıner ◽  
Ömer Şahin ◽  
Deniz Çakmaz ◽  
Gökhan Kaplan ◽  
Kerem Kaya ◽  
...  

Novel 7-diethylaminocoumarin based dyes showed high sensitivity and selectivity to cyanide anions in both organic and aqueous solutions, which was observed by a drastic increment in the emission intensity.


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