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Mirabella DA, Aldao CM. Dependence of n-Type Metal-Oxide Gas Sensor Response on the Pressure of Oxygen and Reducing Gases. ACS Sens 2024. [PMID: 38591496 DOI: 10.1021/acssensors.3c02674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024]
Abstract
The adsorption of oxygen and its reaction with target gases are the basis of the gas detection mechanism by using metal oxides. Here, we present a theoretical analysis of the sensor response, within the ionosorption model, for an n-type polycrystalline semiconductor. Our goal of our work is to reveal the mechanisms of gas sensing from a fundamental point of view. We revisit the existing models in which the sensor response presents a power-law behavior with a reducing gas partial pressure. Then, we show, based on the Wolkenstein theory of chemisorption, that the sensor response depends not only on the reducing gas partial pressure but also on the oxygen partial pressure. We also find that the obtained sensor response does not explicitly depend on the grain size, and if it does, it is exclusively through the rate constants related to the involved reactions.
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Affiliation(s)
- Daniel A Mirabella
- Institute of Scientific and Technological Research in Electronics (ICYTE), University of Mar del Plata and National Research Council (CONICET), Juan B. Justo 4302, Mar del Plata B7608FDQ, Argentina
| | - Celso M Aldao
- Institute of Scientific and Technological Research in Electronics (ICYTE), University of Mar del Plata and National Research Council (CONICET), Juan B. Justo 4302, Mar del Plata B7608FDQ, Argentina
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2
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Ikim MI, Gromov VF, Gerasimov GN, Spiridonova EY, Erofeeva AR, Kurmangaleev KS, Polunin KS, Ilegbusi OJ, Trakhtenberg LI. Structure, Conductivity, and Sensor Properties of Nanosized ZnO-In 2O 3 Composites: Influence of Synthesis Method. Micromachines (Basel) 2023; 14:1685. [PMID: 37763848 PMCID: PMC10535064 DOI: 10.3390/mi14091685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/25/2023] [Accepted: 08/27/2023] [Indexed: 09/29/2023]
Abstract
The influence of the method used for synthesizing ZnO-In2O3 composites (nanopowder mixing, impregnation, and hydrothermal method) on the structure, conductivity, and sensor properties is investigated. With the nanopowder mixing, the size of the parent nanoparticles in the composite remains practically unchanged in the range of 50-100 nm. The impregnation composites consist of 70 nm In2O3 nanoparticles with ZnO nanoclusters < 30 nm in size located on its surface. The nanoparticles in the hydrothermal composites have a narrow size distribution in the range of 10-20 nm. The specific surface of hydrothermal samples is five times higher than that of impregnated samples. The sensor response of the impregnated composite to 1100 ppm H2 is 1.3-1.5 times higher than the response of the mixed composite. Additives of 15-20 and 85 wt.% ZnO to mixed and impregnated composites lead to an increase in the response compared with pure In2O3. In the case of hydrothermal composite, up to 20 wt.% ZnO addition leads to a decrease in response, but 65 wt.% ZnO addition increases response by almost two times compared with pure In2O3. The sensor activity of a hydrothermal composite depends on the phase composition of In2O3. The maximum efficiency is reached for the composite containing cubic In2O3 and the minimum for rhombohedral In2O3. An explanation is provided for the observed effects.
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Affiliation(s)
- Mariya I Ikim
- N.N. Semenov Federal Research Center for Chemical Physics of RAS, Moscow 119991, Russia
| | - Vladimir F Gromov
- N.N. Semenov Federal Research Center for Chemical Physics of RAS, Moscow 119991, Russia
| | - Genrikh N Gerasimov
- N.N. Semenov Federal Research Center for Chemical Physics of RAS, Moscow 119991, Russia
| | - Elena Y Spiridonova
- N.N. Semenov Federal Research Center for Chemical Physics of RAS, Moscow 119991, Russia
| | - Anastasiya R Erofeeva
- N.N. Semenov Federal Research Center for Chemical Physics of RAS, Moscow 119991, Russia
| | - Kairat S Kurmangaleev
- N.N. Semenov Federal Research Center for Chemical Physics of RAS, Moscow 119991, Russia
| | - Kirill S Polunin
- N.N. Semenov Federal Research Center for Chemical Physics of RAS, Moscow 119991, Russia
| | - Olusegun J Ilegbusi
- Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816, USA
| | - Leonid I Trakhtenberg
- N.N. Semenov Federal Research Center for Chemical Physics of RAS, Moscow 119991, Russia
- Chemical Faculty, Lomonosov Moscow State University, Moscow 119991, Russia
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3
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Astolfi M, Rispoli G, Gherardi S, Zonta G, Malagù C. Reproducibility and Repeatability Tests on (SnTiNb)O 2 Sensors in Detecting ppm-Concentrations of CO and Up to 40% of Humidity: A Statistical Approach. Sensors (Basel) 2023; 23:1983. [PMID: 36850578 PMCID: PMC9964738 DOI: 10.3390/s23041983] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/01/2023] [Accepted: 02/08/2023] [Indexed: 06/18/2023]
Abstract
Nowadays, most medical-diagnostic, environmental monitoring, etc. devices employ sensors whose fabrication reproducibility and response repeatability assessment are crucial. The former consists of large-scale sensor manufacture through a standardized process with almost identical morphology and behavior, while the latter consists of giving the same response upon repeating the same stimulus. The thermo-activated chemoresistive sensors, which change their conductance by interacting with the molecules composing the surrounding gas, are currently employed in many devices: in particular, thick-film (SnTiNb)O2 nanosensors were demonstrated to be particularly suitable in the medical and biological fields. Therefore, a set of thirteen of them, randomly selected from the same screen-printing deposition, were laboratory tested, and the outcomes were statistically analyzed in order to assess their consistency. At first, the working temperature that maximized both the sensor sensitivity and response repeatability was identified. Then, the sensors were subjected to different gas concentrations and humidities at this optimal working temperature. It resulted in the (SnTiNb)O2 nanosensors detecting and discriminating CO concentrations as low as 1 ppm and at high humidity degrees (up to 40%) with high repeatability since the response relative standard error ranged from 0.8 to 3.3% for CO and from 3.6 to 5.4% for water vapor.
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Affiliation(s)
- Michele Astolfi
- Department of Physics and Earth Sciences (UNIFE), Via Saragat 1, 44124 Ferrara, Italy
- SCENT S.r.l., Via Quadrifoglio 11, 44124 Ferrara, Italy
| | - Giorgio Rispoli
- Department of Neuroscience and Rehabilitation, Via Luigi Borsari 46, 44121 Ferrara, Italy
| | | | - Giulia Zonta
- Department of Physics and Earth Sciences (UNIFE), Via Saragat 1, 44124 Ferrara, Italy
- SCENT S.r.l., Via Quadrifoglio 11, 44124 Ferrara, Italy
| | - Cesare Malagù
- Department of Physics and Earth Sciences (UNIFE), Via Saragat 1, 44124 Ferrara, Italy
- SCENT S.r.l., Via Quadrifoglio 11, 44124 Ferrara, Italy
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4
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Ikim MI, Gerasimov GN, Gromov VF, Ilegbusi OJ, Trakhtenberg LI. Synthesis, Structural and Sensor Properties of Nanosized Mixed Oxides Based on In 2O 3 Particles. Int J Mol Sci 2023; 24:ijms24021570. [PMID: 36675093 PMCID: PMC9863344 DOI: 10.3390/ijms24021570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 01/14/2023] Open
Abstract
The paper considers the relationship between the structure and properties of nanostructured conductometric sensors based on binary mixtures of semiconductor oxides designed to detect reducing gases in the environment. The sensor effect in such systems is determined by the chemisorption of molecules on the surface of catalytically active particles and the transfer of chemisorbed products to electron-rich nanoparticles, where these products react with the analyzed gas. In this regard, the role is evaluated of the method of synthesizing the composites, the catalytic activity of metal oxides (CeO2, SnO2, ZnO), and the type of conductivity of metal oxides (Co3O4, ZrO2) in the sensor process. The effect of oxygen vacancies present in the composites on the performance characteristics is also considered. Particular attention is paid to the influence of the synthesis procedure for preparing sensitive layers based on CeO2-In2O3 on the structure of the resulting composites, as well as their conductive and sensor properties.
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Affiliation(s)
- Mariya I. Ikim
- N.N. Semenov Federal Research Center for Chemical Physics of RAS, Moscow 119991, Russia
| | - Genrikh N. Gerasimov
- N.N. Semenov Federal Research Center for Chemical Physics of RAS, Moscow 119991, Russia
| | - Vladimir F. Gromov
- N.N. Semenov Federal Research Center for Chemical Physics of RAS, Moscow 119991, Russia
| | - Olusegun J. Ilegbusi
- Biomedical and Process Modeling Lab, University of Central Florida, Orlando, FL 32816, USA
| | - Leonid I. Trakhtenberg
- N.N. Semenov Federal Research Center for Chemical Physics of RAS, Moscow 119991, Russia
- Moscow Institute of Physics and Technology, State University, Dolgoprudny 141701, Russia
- Chemical Faculty, Lomonosov Moscow State University, Moscow 119991, Russia
- Correspondence:
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Korotcenkov G, Tolstoy VP. Current Trends in Nanomaterials for Metal Oxide-Based Conductometric Gas Sensors: Advantages and Limitations-Part 2: Porous 2D Nanomaterials. Nanomaterials (Basel) 2023; 13:237. [PMID: 36677992 PMCID: PMC9867534 DOI: 10.3390/nano13020237] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/01/2023] [Accepted: 01/02/2023] [Indexed: 06/17/2023]
Abstract
This article discusses the features of the synthesis and application of porous two-dimensional nanomaterials in developing conductometric gas sensors based on metal oxides. It is concluded that using porous 2D nanomaterials and 3D structures based on them is a promising approach to improving the parameters of gas sensors, such as sensitivity and the rate of response. The limitations that may arise when using 2D structures in gas sensors intended for the sensor market are considered.
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Affiliation(s)
- Ghenadii Korotcenkov
- Department of Physics and Engineering, Moldova State University, 2009 Chisinau, Moldova
| | - Valeri P. Tolstoy
- Institute of Chemistry, Saint Petersburg State University, Saint Petersburg 198504, Russia
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Kumar U, Hsieh HW, Liu YC, Deng ZY, Chen KL, Huang WM, Wu CH. Revealing a Highly Sensitive Sub-ppb-Level NO 2 Gas-Sensing Capability of Novel Architecture 2D/0D MoS 2/SnS Heterostructures with DFT Interpretation. ACS Appl Mater Interfaces 2022; 14:32279-32288. [PMID: 35818995 DOI: 10.1021/acsami.2c03173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In this work, we use a chemical method to design novel 2D-material/0D-quantum dot (MoS2/SnS) heterostructures. Furthermore, the unique 2D/0D heterostructure enhanced the NO2 gas-sensing capability 3 times and increased the sensing recoverability by more than 90%. Advanced characterization tools such as SEM, TEM, XRD, and AFM confirm the formation of MoS2/SnS heterojunction nanomaterials. Using AFM data, the average thickness of the MoS2 layer was found to be 5 nm. The highest sensor response of 0.33 with good repeatability was observed at 250 ppb of NO2. Sensing characterization reveals the ultra-fast response time, that is, 74 s, at 50 ppb of NO2. The limit of detection for detecting NO2 was also found to be very low, that is, 0.54 ppb, by using MoS2/SnS heterostructures. The theoretical calculations based on density functional theory well corroborated and quantified the intermolecular interaction and gas adsorption on the surface of MoS2/SnS.
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Affiliation(s)
- Utkarsh Kumar
- Department of Physics, National Chung Hsing University, Taichung 402, Taiwan
| | - Han-Wei Hsieh
- Institute of Nanoscience, National Chung Hsing University, Taichung 402, Taiwan
| | - Yi-Chen Liu
- Department of Physics, National Chung Hsing University, Taichung 402, Taiwan
| | - Zu-Yin Deng
- Department of Physics, National Chung Hsing University, Taichung 402, Taiwan
| | - Kuen-Lin Chen
- Department of Physics, National Chung Hsing University, Taichung 402, Taiwan
| | - Wen-Min Huang
- Department of Physics, National Chung Hsing University, Taichung 402, Taiwan
| | - Chiu-Hsien Wu
- Department of Physics, National Chung Hsing University, Taichung 402, Taiwan
- Institute of Nanoscience, National Chung Hsing University, Taichung 402, Taiwan
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7
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Saad R, Gamal A, Zayed M, Ahmed AM, Shaban M, BinSabt M, Rabia M, Hamdy H. Fabrication of ZnO/CNTs for Application in CO 2 Sensor at Room Temperature. Nanomaterials (Basel) 2021; 11:3087. [PMID: 34835849 PMCID: PMC8624847 DOI: 10.3390/nano11113087] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 11/17/2022]
Abstract
Thin films of ZnO and ZnO/carbon nanotubes (CNTs) are prepared and used as CO2 gas sensors. The spray pyrolysis method was used to prepare both ZnO and ZnO/CNTs films, with CNTs first prepared using the chemical vapor deposition method (CVD). The chemical structure and optical analyses for all the prepared nanomaterials were performed using X-ray diffraction (XRD), Fourier transformer infrared spectroscopy (FTIR), and UV/Vis spectrophotometer devices, respectively. According to the XRD analysis, the crystal sizes of ZnO and ZnO/CNTs were approximately 50.4 and 65.2 nm, respectively. CNTs have average inner and outer diameters of about 3 and 13 nm respectively, according to the transmitted electron microscope (TEM), and a wall thickness of about 5 nm. The detection of CO2 is accomplished by passing varying rates of the gas from 30 to 150 sccm over the prepared thin-film electrodes. At 150 sccm, the sensitivities of ZnO and ZnO/CNTs sensors are 6.8% and 22.4%, respectively. The ZnO/CNTs sensor has a very stable sensitivity to CO2 gas for 21 days. Moreover, this sensor has a high selectivity to CO2 in comparison with other gases, in which the ZnO/CNTs sensor has a higher sensitivity to CO2 compared to H2 and C2H2.
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Affiliation(s)
- Rana Saad
- Nanophotonics and Applications Laboratory, Physics Department, Faculty of Science, Beni-Suef University, Beni-Suef 62514, Egypt; (R.S.); (A.G.); (M.Z.); (A.M.A.); (M.R.); (H.H.)
| | - Ahmed Gamal
- Nanophotonics and Applications Laboratory, Physics Department, Faculty of Science, Beni-Suef University, Beni-Suef 62514, Egypt; (R.S.); (A.G.); (M.Z.); (A.M.A.); (M.R.); (H.H.)
| | - Mohamed Zayed
- Nanophotonics and Applications Laboratory, Physics Department, Faculty of Science, Beni-Suef University, Beni-Suef 62514, Egypt; (R.S.); (A.G.); (M.Z.); (A.M.A.); (M.R.); (H.H.)
| | - Ashour M. Ahmed
- Nanophotonics and Applications Laboratory, Physics Department, Faculty of Science, Beni-Suef University, Beni-Suef 62514, Egypt; (R.S.); (A.G.); (M.Z.); (A.M.A.); (M.R.); (H.H.)
| | - Mohamed Shaban
- Nanophotonics and Applications Laboratory, Physics Department, Faculty of Science, Beni-Suef University, Beni-Suef 62514, Egypt; (R.S.); (A.G.); (M.Z.); (A.M.A.); (M.R.); (H.H.)
- Department of Physics, Faculty of Science, Islamic University of Madinah, P.O. Box 170, AlMadinah Almonawara 42351, Saudi Arabia
| | - Mohammad BinSabt
- Chemistry Department, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait;
| | - Mohamed Rabia
- Nanophotonics and Applications Laboratory, Physics Department, Faculty of Science, Beni-Suef University, Beni-Suef 62514, Egypt; (R.S.); (A.G.); (M.Z.); (A.M.A.); (M.R.); (H.H.)
- Polymer Research Laboratory, Chemistry Department, Faculty of Science, Beni-Suef University, Beni-Suef 62511, Egypt
| | - Hany Hamdy
- Nanophotonics and Applications Laboratory, Physics Department, Faculty of Science, Beni-Suef University, Beni-Suef 62514, Egypt; (R.S.); (A.G.); (M.Z.); (A.M.A.); (M.R.); (H.H.)
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Gancarz M, Nawrocka A, Rusinek R. Identification of Volatile Organic Compounds and Their Concentrations Using a Novel Method Analysis of MOS Sensors Signal. J Food Sci 2019; 84:2077-2085. [PMID: 31339559 DOI: 10.1111/1750-3841.14701] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/28/2019] [Accepted: 05/23/2019] [Indexed: 12/12/2022]
Abstract
Volatile organic compounds (VOCs) are natural markers useful in rapid assessment of adverse changes occurring in biological material. The use of an electronic nose seems to be a good, fast, and cheap method to determine particular VOCs. This paper presents a new method determination for VOCs and their concentration based on three sensorgram parameters: maximum of normalized sensor response, reaction time, and cleaning time measured from the end of the test to the half value of the maximum of normalized sensor response. The novelty of the method consists in the use for the first time of two parameters: reaction time and cleaning time measured from the end of the test to the half value of the maximum of normalized sensor response. The VOC sensorgrams at different VOC concentrations (26 to 3,842 ppm) were measured by an electronic nose Food Volatile Compound Analyzer (Agrinose) equipped with eight metal oxide semiconductor sensors dedicated to detect different gases. In the present studies, only six sensors that best respond to the VOCs were used. The highest responses to VOCs were obtained for two sensors-TGS2602 and AS-MLV-P2. The results showed that the dependence between the sensorgram parameters on VOC concentration was well described by a logarithmic curve in the whole range of concentrations. Detailed analysis revealed that the cleaning time increases with an increase in the number of carbon atoms in aliphatic molecules. The principal component analysis (PCA) was used to verify the utility of the new three parameters method in VOCs differentiation. The PCA analysis of these parameters showed that maximum of the normalized sensor response alone, which has been used for identification of particular VOCs so far, could not be regarded as a good parameter used for this purpose. Application of all the three parameters gave the best results in VOC identification. The research indicates that the use of three parameters of a volatile compound instead of only one parameter can allow precise determination of substances. Moreover, the results indicate that the analyzed parameters depend on the chemical structure of VOCs.
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Affiliation(s)
- Marek Gancarz
- Inst. of Agrophysics, Polish Academy of Sciences, Do´swiadczalna 4, 20-290, Lublin, Poland
| | - Agnieszka Nawrocka
- Inst. of Agrophysics, Polish Academy of Sciences, Do´swiadczalna 4, 20-290, Lublin, Poland
| | - Robert Rusinek
- Inst. of Agrophysics, Polish Academy of Sciences, Do´swiadczalna 4, 20-290, Lublin, Poland
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Dennis JO, Ahmed AY, Khir MH. Fabrication and Characterization of a CMOS-MEMS Humidity Sensor. Sensors (Basel) 2015; 15:16674-87. [PMID: 26184204 PMCID: PMC4541900 DOI: 10.3390/s150716674] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 06/26/2015] [Accepted: 07/01/2015] [Indexed: 11/16/2022]
Abstract
This paper reports on the fabrication and characterization of a Complementary Metal Oxide Semiconductor-Microelectromechanical System (CMOS-MEMS) device with embedded microheater operated at relatively elevated temperatures (40 °C to 80 °C) for the purpose of relative humidity measurement. The sensing principle is based on the change in amplitude of the device due to adsorption or desorption of humidity on the active material layer of titanium dioxide (TiO2) nanoparticles deposited on the moving plate, which results in changes in the mass of the device. The sensor has been designed and fabricated through a standard 0.35 µm CMOS process technology and post-CMOS micromachining technique has been successfully implemented to release the MEMS structures. The sensor is operated in the dynamic mode using electrothermal actuation and the output signal measured using a piezoresistive (PZR) sensor connected in a Wheatstone bridge circuit. The output voltage of the humidity sensor increases from 0.585 mV to 30.580 mV as the humidity increases from 35% RH to 95% RH. The output voltage is found to be linear from 0.585 mV to 3.250 mV as the humidity increased from 35% RH to 60% RH, with sensitivity of 0.107 mV/% RH; and again linear from 3.250 mV to 30.580 mV as the humidity level increases from 60% RH to 95% RH, with higher sensitivity of 0.781 mV/% RH. On the other hand, the sensitivity of the humidity sensor increases linearly from 0.102 mV/% RH to 0.501 mV/% RH with increase in the temperature from 40 °C to 80 °C and a maximum hysteresis of 0.87% RH is found at a relative humidity of 80%. The sensitivity is also frequency dependent, increasing from 0.500 mV/% RH at 2 Hz to reach a maximum value of 1.634 mV/% RH at a frequency of 12 Hz, then decreasing to 1.110 mV/% RH at a frequency of 20 Hz. Finally, the CMOS-MEMS humidity sensor showed comparable response, recovery, and repeatability of measurements in three cycles as compared to a standard sensor that directly measures humidity in % RH.
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Affiliation(s)
- John-Ojur Dennis
- Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Perak Darul Ridzuan 32610, Malaysia.
| | - Abdelaziz-Yousif Ahmed
- Department of Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Perak Darul Ridzuan 32610, Malaysia.
| | - Mohd-Haris Khir
- Department of Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Perak Darul Ridzuan 32610, Malaysia.
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10
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Lu J, Zhang X, Wu X, Dai Z, Zhang J. A Ni-Doped Carbon Nanotube Sensor for Detecting Oil-Dissolved Gases in Transformers. Sensors (Basel) 2015; 15:13522-32. [PMID: 26066989 PMCID: PMC4507586 DOI: 10.3390/s150613522] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 05/13/2015] [Accepted: 06/02/2015] [Indexed: 11/26/2022]
Abstract
C2H2, C2H4, and C2H6 are important oil-dissolved gases in power transformers. Detection of the composition and content of oil-dissolved gases in transformers is very significant in the diagnosis and assessment of the state of transformer operations. The commonly used oil-gas analysis methods have many disadvantages, so this paper proposes a Ni-doped carbon nanotube (Ni-CNT) gas sensor to effectively detect oil-dissolved gases in a transformer. The gas-sensing properties of the sensor to C2H2, C2H4, and C2H6 were studied using the test device. Based on the density functional theory (DFT) the adsorption behaviors of the three gases on intrinsic carbon nanotubes (CNTs) and Ni-CNTs were calculated. The adsorption energy, charge transfer, and molecular frontier orbital of the adsorption system were also analyzed. Results showed that the sensitivity of the CNT sensor to the three kinds of gases was in the following order: C2H2 > C2H4 > C2H6. Moreover, the doped Ni improved the sensor response, and the sensor response and gas concentration have a good linear relationship.
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Affiliation(s)
- Jia Lu
- State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Shapingba District, Chongqing 400044, China.
| | - Xiaoxing Zhang
- State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Shapingba District, Chongqing 400044, China.
| | - Xiaoqing Wu
- State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Shapingba District, Chongqing 400044, China.
| | - Ziqiang Dai
- State Grid Guizhou Liupanshui Power Supply Company, Liupanshui 553000, China.
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11
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Zhang X, Zhang J, Jia Y, Xiao P, Tang J. TiO2 nanotube array sensor for detecting the SF6 decomposition product SO2. Sensors (Basel) 2012; 12:3302-13. [PMID: 22737009 DOI: 10.3390/s120303302] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 03/02/2012] [Accepted: 03/05/2012] [Indexed: 11/30/2022]
Abstract
The detection of partial discharge through analysis of SF6 gas components in gas-insulated switchgear, is significant for the diagnosis and assessment of the operating state of power equipment. The present study proposes the use of a TiO2 nanotube array sensor for detecting the SF6 decomposition product SO2, and the application of the anodic oxidation method for the directional growth of highly ordered TiO2 nanotube arrays. The sensor response of 10–50 ppm SO2 gas is tested, and the sensitive response mechanism is discussed. The test results show that the TiO2 nanotube sensor array has good response to SO2 gas, and by ultraviolet radiation, the sensor can remove attached components very efficiently, shorten recovery time, reduce chemical poisoning, and prolong the life of the components.
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12
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Lee SC, Kim SY, Lee WS, Jung SY, Hwang BW, Ragupathy D, Lee DD, Lee SY, Kim JC. Effects of textural properties on the response of a SnO2-based gas sensor for the detection of chemical warfare agents. Sensors (Basel) 2011; 11:6893-904. [PMID: 22163991 PMCID: PMC3231691 DOI: 10.3390/s110706893] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 06/29/2011] [Accepted: 06/30/2011] [Indexed: 11/16/2022]
Abstract
The sensing behavior of SnO2-based thick film gas sensors in a flow system in the presence of a very low concentration (ppb level) of chemical agent simulants such as acetonitrile, dipropylene glycol methyl ether (DPGME), dimethyl methylphosphonate (DMMP), and dichloromethane (DCM) was investigated. Commercial SnO2 [SnO2(C)] and nano-SnO2 prepared by the precipitation method [SnO2(P)] were used to prepare the SnO2 sensor in this study. In the case of DCM and acetonitrile, the SnO2(P) sensor showed higher sensor response as compared with the SnO2(C) sensors. In the case of DMMP and DPGME, however, the SnO2(C) sensor showed higher responses than those of the SnO2(P) sensors. In particular, the response of the SnO2(P) sensor increased as the calcination temperature increased from 400 °C to 800 °C. These results can be explained by the fact that the response of the SnO2-based gas sensor depends on the textural properties of tin oxide and the molecular size of the chemical agent simulant in the detection of the simulant gases (0.1–0.5 ppm).
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Affiliation(s)
- Soo Chool Lee
- Department of Chemical Engineering, Kyungpook National University, Daegu 702-701, Korea.
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Wright JD, Johnson AN, Moldover MR. Design and Uncertainty Analysis for a PVTt Gas Flow Standard. J Res Natl Inst Stand Technol 2003; 108:21-47. [PMID: 27413592 PMCID: PMC4844527 DOI: 10.6028/jres.108.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/27/2002] [Indexed: 06/05/2023]
Abstract
A new pressure, volume, temperature, and, time (PVTt) primary gas flow standard at the National Institute of Standards and Technology has an expanded uncertainty (k = 2) of between 0.02 % and 0.05 %. The standard spans the flow range of 1 L/min to 2000 L/min using two collection tanks and two diverter valve systems. The standard measures flow by collecting gas in a tank of known volume during a measured time interval. We describe the significant and novel features of the standard and analyze its uncertainty. The gas collection tanks have a small diameter and are immersed in a uniform, stable, thermostatted water bath. The collected gas achieves thermal equilibrium rapidly and the uncertainty of the average gas temperature is only 7 mK (22 × 10(-6) T). A novel operating method leads to essentially zero mass change in and very low uncertainty contributions from the inventory volume. Gravimetric and volume expansion techniques were used to determine the tank and the inventory volumes. Gravimetric determinations of collection tank volume made with nitrogen and argon agree with a standard deviation of 16 × 10(-6) VT . The largest source of uncertainty in the flow measurement is drift of the pressure sensor over time, which contributes relative standard uncertainty of 60 × 10(-6) to the determinations of the volumes of the collection tanks and to the flow measurements. Throughout the range 3 L/min to 110 L/min, flows were measured independently using the 34 L and the 677 L collection systems, and the two systems agreed within a relative difference of 150 × 10(-6). Double diversions were used to evaluate the 677 L system over a range of 300 L/min to 1600 L/min, and the relative differences between single and double diversions were less than 75 × 10(-6).
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Affiliation(s)
- John D. Wright
- National Institute of Standards and Technology, Gaithersburg, MD 20899-0001
| | - Aaron N. Johnson
- National Institute of Standards and Technology, Gaithersburg, MD 20899-0001
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