Rational Synthesis and Optimization of Multifunctional Solid-State Gas Sensors

2004 ◽  
Vol 828 ◽  
Author(s):  
Johannes Schwank ◽  
Ghenadii Korotcenkov
Keyword(s):  
Solid State ◽  
Gas Sensors ◽  
Active Sites ◽  
Gas Sensing ◽  
Heterogeneous Systems ◽  
Sensor Applications ◽  
Sensing Applications ◽  
Long Time ◽  
Overall Performance ◽  
Scale Design

ABSTRACTA new approach is discussed for the rational synthesis and development of optimized multifunctional solid-state gas sensors. Multifunctionality—the incorporation of multiple types of reactivities into a material, such as acid and/or base functionalities, oxidation and/or reduction functionalities, etc.—isa requirement in many gas sensing applications. The front end of many gas sensors contains catalytic layers, so that optimization of catalysts and optimization of gas sensors can be carried out in a synergistic fashion.Multifunctionality presents unique challenges to rational catalyst and sensor systems development because the overall performance of the material is a convolution of the performance of the various subcomponents, and optimization of these individual subcomponents in isolation does not necessarily lead to optimal, or even acceptable, overall performance. A major obstacle to dealing with these difficulties is the inherent complexity of heterogeneous systems prepared by traditional approaches, which makes it difficult to unambiguously identify the compositions and morphologies of the local active sites and their interactions. Further complicating the problem is the requirement to function in environments that can vary on both short and long time scales. A key to understanding, controlling, and optimizing these materials is the ability to produce and study well-defined sensor materials with well-defined composition and morphology, with the flexibility to vary the composition easily without jeopardizing the structural uniformity.The development of new or improved materials for gas sensor applications requires a search for novel and innovative approaches to the nano-scale design of these materials. The use of the technology of surface modification by successive ionic layer deposition (SILD) method is such an innovative approach that will be discussed in this paper.

Nanomaterial-based gas sensors used for breath diagnosis

2020 ◽  
Vol 8 (16) ◽  
pp. 3231-3248 ◽  
Author(s):  
Xinyuan Zhou ◽  
Zhenjie Xue ◽  
Xiangyu Chen ◽  
Chuanhui Huang ◽  
Wanqiao Bai ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Gas Sensors ◽  
Active Sites ◽  
Gas Sensing ◽  
High Surface ◽  
Volume Ratio ◽  
Sensing Applications ◽  
Enormous Number

Gas-sensing applications commonly use nanomaterials (NMs) because of their unique physicochemical properties, including a high surface-to-volume ratio, enormous number of active sites, controllable morphology, and potential for miniaturisation.

scholarly journals Optimization of a Low-Power Chemoresistive Gas Sensor: Predictive Thermal Modelling and Mechanical Failure Analysis

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 783 ◽  
Author(s):  
Andrea Gaiardo ◽  
David Novel ◽  
Elia Scattolo ◽  
Michele Crivellari ◽  
Antonino Picciotto ◽  
...  
Keyword(s):  
Low Power ◽  
Failure Analysis ◽  
Gas Sensors ◽  
High Performance ◽  
Gas Sensing ◽  
Mechanical Failure ◽  
Sensing Applications ◽  
Theoretical Approaches ◽  
Sensing Material ◽  
Silicon Bulk

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.

scholarly journals Advanced development of metal oxide nanomaterials for H2 gas sensing applications

2021 ◽  
Author(s):  
Yushu Shi ◽  
Huiyan Xu ◽  
Tongyao Liu ◽  
Shah Zeb ◽  
Yong Nie ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Gas Sensors ◽  
Gas Sensing ◽  
The Past ◽  
Sensing Applications ◽  
The Future ◽  
Metal Oxide Nanomaterials ◽  
Nanomaterials Synthesis ◽  
Advanced Development

The scheme of the structure of this review includes an introduction from the metal oxide nanomaterials’ synthesis to application in H2 gas sensors—a vision from the past to the future.

SnO2 Nano/Microfibers for Gas Sensors

2020 ◽  
Vol 405 ◽  
pp. 324-329
Author(s):  
Erika Mudra ◽  
Ivan Shepa ◽  
Alexandra Kovalcikova ◽  
Ondrej Milkovič ◽  
Jan Dusza
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Band Gap Energy ◽  
Calcination Process ◽  
Sensing Applications ◽  
Amorphous Nature ◽  
Coating Method ◽  
Type Semiconductor

SnO2 is an n-type semiconductor with the band gap energy of 3.6 eV. It has been widely studied for gas sensing applications, the sensitivity of which can be easily tuned by the operating temperature. The presented paper is focused on the preparation and detailed characterization of the hollow SnO2 nano/microfibers suitable for gas detection sensors. Ceramic SnO2 fibers were produced by needleless electrospinning and followed by the calcination process. The characterization was performed by SEM, TEM, XRD, and Raman spectroscopy. The precursor PVP/SnO2 fibers had amorphous nature. The calcination of the electro spun precursor resulted in the formation of hollow crystalline fibrous structures. The formation mechanism of hollow fibers has been described. Subsequently, a homogeneous fibrous layer was created by the spin coating method for gas sensing applications.

scholarly journals Gas Sensing Properties of Mg-Incorporated Metal–Organic Frameworks

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3323 ◽  
Author(s):  
Jae-Hyoung Lee ◽  
Thanh-Binh Nguyen ◽  
Duy-Khoi Nguyen ◽  
Jae-Hun Kim ◽  
Jin-Young Kim ◽  
...  
Keyword(s):  
Pore Size ◽  
Gas Sensors ◽  
Gas Sensing ◽  
High Surface ◽  
Metal Organic Frameworks ◽  
Kinetic Properties ◽  
Sensing Properties ◽  
Sensing Applications ◽  
Gas Sensing Properties ◽  
Metal Organic

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.

scholarly journals Gas sensors using ordered macroporous oxide nanostructures

2019 ◽  
Vol 1 (5) ◽  
pp. 1626-1639 ◽  
Author(s):  
Zhengfei Dai ◽  
Tingting Liang ◽  
Jong-Heun Lee
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Sensing Applications ◽  
Oxide Nanostructures ◽  
Ordered Macroporous

Summary and perspective on gas-sensing applications of ordered macroporous oxide nanostructures have been outlined in this review.

CNTFET Gas Sensors Using SWCNT Mats: Method for Low-cost Fabrication, Solution to Improve Selectivity, Experimental Results using Interfering Agents

2009 ◽  
Vol 1204 ◽  
Author(s):  
Paolo Bondavalli ◽  
Louis Gorintin ◽  
Pierre Legagneux ◽  
Didier Pribat ◽  
Laurent Caillier ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Gas Sensors ◽  
Field Effect ◽  
Gas Sensing ◽  
Field Effect Transistors ◽  
Low Cost ◽  
Experimental Results ◽  
Flexible Substrates ◽  
Metal Electrodes ◽  
Sensing Applications

AbstractThe first paper showing the great potentiality of Carbon Nanotubes Field Effect transistors (CNTFETs) for gas sensing applications was published in 2000 [1]. It has been demonstrated that the performances of this kind of sensors are extremely interesting: a sensitivity of around 100ppt (e.g. for NO2 [2]) has been achieved in 2003 and several techniques to improve selectivity have been tested with very promising results [2]. The main issues that have not allowed, up to now, these devices to strike more largely the market of sensors, have been the lack of an industrial method to obtain low-cost devices, a demonstration of their selectivity in relevant environments and finally a deeper study on the effect of humidity and the possible solutions to reduce it. This contribution deals with CNTFETs based sensors fabricated using air-brush technique deposition on large surfaces. Compared to our last contribution [3], we have optimized the air-brush technique in order to obtain high performances transistors (Log(Ion)/Log(Ioff) ∼ 5/6) with highly reproducible characteristics : this is a key point for the industrial exploitation. We have developed a machine which allows us the dynamic deposition on heated substrates of the SWCNT solutions, improving dramatically the uniformity of the SWCNT mats. We have performed tests using different solvents that could be adapted as a function of the substrates (e.g. flexible substrates). Moreover these transistors have been achieved using different metal electrodes (patented approach [4]) in order to improve selectivity. Results of tests using NO2, NH3 with concentrations between ∼ 1ppm and 10ppm will be shown during the meeting.

scholarly journals The Use of Copper Oxide Thin Films in Gas-Sensing Applications

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 425 ◽  
Author(s):  
Artur Rydosz
Keyword(s):  
Thin Film ◽  
Copper Oxide ◽  
Gas Sensors ◽  
Gas Sensing ◽  
Oxide Thin Film ◽  
Exhaled Breath ◽  
Long Term Stability ◽  
Advantages And Disadvantages ◽  
Sensing Applications ◽  
Commercial Applications

In this work, the latest achievements in the field of copper oxide thin film gas sensors are presented and discussed. Several methods and deposition techniques are shown with their advantages and disadvantages for commercial applications. Recently, CuO thin film gas sensors have been studied to detect various compounds, such as: nitrogen oxides, carbon oxides, hydrogen sulfide, ammonia, as well as several volatile organic compounds in many different applications, e.g., agriculture. The CuO thin film gas sensors exhibited high 3-S parameters (sensitivity, selectivity, and stability). Furthermore, the possibility to function at room temperature with long-term stability was proven as well, which makes this material very attractive in gas-sensing applications, including exhaled breath analysis.

Enhancement of the gas sensing performance of carbon nanotube networked films based on their electrophoretic functionalization with gold nanoparticles

2015 ◽  
Vol 1786 ◽  
pp. 37-42 ◽  
Author(s):  
E. Dilonardo ◽  
M. Penza ◽  
M. Alvisi ◽  
C. Di Franco ◽  
D. Suriano ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Gas Sensitivity ◽  
Sensing Applications ◽  
Active Layers ◽  
Resistive Gas Sensors ◽  
Ppm Level ◽  
Fine Tune ◽  
Pollutant Gases ◽  
Higher Sensitivity

ABSTRACTControlled amounts of colloidal Au nanoparticles (NPs), electrochemically pre-synthesized, were directly deposited on MWCNTs sensor devices by electrophoresis. Pristine and Au-functionalized MWCNT networked films were tested as active layers in resistive gas sensors for detection of pollutant gases. Au-modified CNT-chemiresistor demonstrated higher sensitivity to NO2 detecting up to sub-ppm level compared to pristine one. The investigation of the cross-sensitivity towards other pollutant gases revealed the decrease of the sensitivity to NO2 with the increase of Au content, and, on the other side, the increase of that to H2S; therefore the fine tune of the metal loading on CNTs has allowed to control not only the gas sensitivity but also the selectivity towards a specific gaseous analyte. Finally, the sensing properties of Au-decorated CNT sensor seem to be promising in environmental and automotive gas sensing applications, based on low power consumption and moderate operating temperature.

scholarly journals Fiber Optic Gas Sensors Based on Lossy Mode Resonances and Sensing Materials Used Therefor: A Comprehensive Review

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 731
Author(s):  
Ignacio Vitoria ◽  
Carlos Ruiz Zamarreño ◽  
Aritz Ozcariz ◽  
Ignacio R. Matias
Keyword(s):  
Optical Fiber ◽  
Gas Sensors ◽  
Gas Sensing ◽  
Optical Fiber Sensors ◽  
Industrial Sector ◽  
Fiber Sensors ◽  
Sensing Applications ◽  
Wide Range ◽  
Materials Used ◽  
Diagnostic Applications

Pollution in cities induces harmful effects on human health, which continuously increases the global demand of gas sensors for air quality control and monitoring. In the same manner, the industrial sector requests new gas sensors for their productive processes. Moreover, the association between exhaled gases and a wide range of diseases or health conditions opens the door for new diagnostic applications. The large number of applications for gas sensors has permitted the development of multiple sensing technologies. Among them, optical fiber gas sensors enable their utilization in remote locations, confined spaces or hostile environments as well as corrosive or explosive atmospheres. Particularly, Lossy Mode Resonance (LMR)-based optical fiber sensors employ the traditional metal oxides used for gas sensing purposes for the generation of the resonances. Some research has been conducted on the development of LMR-based optical fiber gas sensors; however, they have not been fully exploited yet and offer optimal possibilities for improvement. This review gives the reader a complete overview of the works focused on the utilization of LMR-based optical fiber sensors for gas sensing applications, summarizing the materials used for the development of these sensors as well as the fabrication procedures and the performance of these devices.

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