Journal articles: 'Semiconducting Metal Oxide Gas Sensors Theory'

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Mirzaei, Ali, Hyoun Woo Kim, Sang Sub Kim, and Giovanni Neri. "Nanostructured Semiconducting Metal Oxide Gas Sensors for Acetaldehyde Detection." Chemosensors 7, no. 4 (November 13, 2019): 56. http://dx.doi.org/10.3390/chemosensors7040056.

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Volatile organic compounds (VOCs) are among the most abundant air pollutants. Their high concentrations can adversely affect the human body, and therefore, early detection of VOCs is of outmost importance. Among the different VOCs, in this review paper we have focused our attention to the monitoring of acetaldehyde by chemiresistive gas sensors fabricated from nanostructured semiconducting metal oxides. These sensors can not only provide a high sensing signal for detection of acetaldehyde but also high thermal and mechanical stability along with a low price. This review paper is divided into three major sections. First, we will introduce acetaldehyde as an important VOC and the importance of its detection. Then, the fundamentals of chemiresistive gas sensors will be briefly presented, and in the last section, a survey of the literature on acetaldehyde gas sensors will be presented. The working mechanism of acetaldehyde sensors, their structures, and configurations are reviewed. Finally, the future development outlook and potential applications are discussed, giving a complete panoramic view for researchers working and interested in acetaldehyde detection for different purposes in many fundamental and applicative fields.

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Wang, Ying, Li Duan, Zhen Deng, and Jianhui Liao. "Electrically Transduced Gas Sensors Based on Semiconducting Metal Oxide Nanowires." Sensors 20, no. 23 (November 27, 2020): 6781. http://dx.doi.org/10.3390/s20236781.

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Semiconducting metal oxide-based nanowires (SMO-NWs) for gas sensors have been extensively studied for their extraordinary surface-to-volume ratio, high chemical and thermal stabilities, high sensitivity, and unique electronic, photonic and mechanical properties. In addition to improving the sensor response, vast developments have recently focused on the fundamental sensing mechanism, low power consumption, as well as novel applications. Herein, this review provides a state-of-art overview of electrically transduced gas sensors based on SMO-NWs. We first discuss the advanced synthesis and assembly techniques for high-quality SMO-NWs, the detailed sensor architectures, as well as the important gas-sensing performance. Relationships between the NWs structure and gas sensing performance are established by understanding general sensitization models related to size and shape, crystal defect, doped and loaded additive, and contact parameters. Moreover, major strategies for low-power gas sensors are proposed, including integrating NWs into microhotplates, self-heating operation, and designing room-temperature gas sensors. Emerging application areas of SMO-NWs-based gas sensors in disease diagnosis, environmental engineering, safety and security, flexible and wearable technology have also been studied. In the end, some insights into new challenges and future prospects for commercialization are highlighted.

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Kanan, Sofian, Oussama El-Kadri, Imad Abu-Yousef, and Marsha Kanan. "Semiconducting Metal Oxide Based Sensors for Selective Gas Pollutant Detection." Sensors 9, no. 10 (October 16, 2009): 8158–96. http://dx.doi.org/10.3390/s91008158.

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Huang, Jin, and Qing Wan. "Gas Sensors Based on Semiconducting Metal Oxide One-Dimensional Nanostructures." Sensors 9, no. 12 (December 4, 2009): 9903–24. http://dx.doi.org/10.3390/s91209903.

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Lahlalia, Ayoub, Olivier Le Neel, Ravi Shankar, Siegfried Selberherr, and Lado Filipovic. "Improved Sensing Capability of Integrated Semiconducting Metal Oxide Gas Sensor Devices." Sensors 19, no. 2 (January 17, 2019): 374. http://dx.doi.org/10.3390/s19020374.

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Semiconducting metal oxide (SMO) gas sensors were designed, fabricated, and characterized in terms of their sensing capability and the thermo-mechanical behavior of the micro-hotplate. The sensors demonstrate high sensitivity at low concentrations of volatile organic compounds (VOCs) at a low power consumption of 10.5 mW. In addition, the sensors realize fast response and recovery times of 20 s and 2.3 min, respectively. To further improve the baseline stability and sensing response characteristics at low power consumption, a novel sensor is conceived of and proposed. Tantalum aluminum (TaAl) is used as a microheater, whereas Pt-doped SnO2 is used as a thin film sensing layer. Both layers were deposited on top of a porous silicon nitride membrane. In this paper, two designs are characterized by simulations and experimental measurements, and the results are comparatively reported. Simultaneously, the impact of a heat pulsing mode and rubber smartphone cases on the sensing performance of the gas sensor are highlighted.

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Castañeda, L., M. Gonzalez-Alatriste, and M. Avendaño-Alejo. "Thin Solid Films Semiconducting Metal Oxide Gas Sensors: A Brief Review." Sensor Letters 14, no. 4 (April 1, 2016): 331–45. http://dx.doi.org/10.1166/sl.2016.3631.

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Potyrailo, Radislav A., Steven Go, Daniel Sexton, Xiaxi Li, Nasr Alkadi, Andrei Kolmakov, Bruce Amm, et al. "Extraordinary performance of semiconducting metal oxide gas sensors using dielectric excitation." Nature Electronics 3, no. 5 (May 2020): 280–89. http://dx.doi.org/10.1038/s41928-020-0402-3.

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Horsfall, Lauren A., David C. Pugh, Christopher S. Blackman, and Ivan P. Parkin. "An array of WO3 and CTO heterojunction semiconducting metal oxide gas sensors used as a tool for explosive detection." Journal of Materials Chemistry A 5, no. 5 (2017): 2172–79. http://dx.doi.org/10.1039/c6ta08253j.

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Moseley, Patrick T. "Progress in the development of semiconducting metal oxide gas sensors: a review." Measurement Science and Technology 28, no. 8 (June 28, 2017): 082001. http://dx.doi.org/10.1088/1361-6501/aa7443.

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Song, Young Geun, Young-Seok Shim, Sangtae Kim, Soo Deok Han, Hi Gyu Moon, Myoung Sub Noh, Kwangjae Lee, et al. "Downsizing gas sensors based on semiconducting metal oxide: Effects of electrodes on gas sensing properties." Sensors and Actuators B: Chemical 248 (September 2017): 949–56. http://dx.doi.org/10.1016/j.snb.2017.02.035.

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Bârsan, N. "Transduction in Semiconducting Metal Oxide Based Gas Sensors - Implications of the Conduction Mechanism." Procedia Engineering 25 (2011): 100–103. http://dx.doi.org/10.1016/j.proeng.2011.12.025.

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Lahlalia, Ayoub, Lado Filipovic, and Siegfried Selberherr. "Modeling and Simulation of Novel Semiconducting Metal Oxide Gas Sensors for Wearable Devices." IEEE Sensors Journal 18, no. 5 (March 1, 2018): 1960–70. http://dx.doi.org/10.1109/jsen.2018.2790001.

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Nikolic, Maria Vesna, Vladimir Milovanovic, Zorka Z. Vasiljevic, and Zoran Stamenkovic. "Semiconductor Gas Sensors: Materials, Technology, Design, and Application." Sensors 20, no. 22 (November 23, 2020): 6694. http://dx.doi.org/10.3390/s20226694.

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This paper presents an overview of semiconductor materials used in gas sensors, their technology, design, and application. Semiconductor materials include metal oxides, conducting polymers, carbon nanotubes, and 2D materials. Metal oxides are most often the first choice due to their ease of fabrication, low cost, high sensitivity, and stability. Some of their disadvantages are low selectivity and high operating temperature. Conducting polymers have the advantage of a low operating temperature and can detect many organic vapors. They are flexible but affected by humidity. Carbon nanotubes are chemically and mechanically stable and are sensitive towards NO and NH3, but need dopants or modifications to sense other gases. Graphene, transition metal chalcogenides, boron nitride, transition metal carbides/nitrides, metal organic frameworks, and metal oxide nanosheets as 2D materials represent gas-sensing materials of the future, especially in medical devices, such as breath sensing. This overview covers the most used semiconducting materials in gas sensing, their synthesis methods and morphology, especially oxide nanostructures, heterostructures, and 2D materials, as well as sensor technology and design, application in advance electronic circuits and systems, and research challenges from the perspective of emerging technologies.

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Dutta, Taposhree, Tanzila Noushin, Shawana Tabassum, and Satyendra K. Mishra. "Road Map of Semiconductor Metal-Oxide-Based Sensors: A Review." Sensors 23, no. 15 (August 1, 2023): 6849. http://dx.doi.org/10.3390/s23156849.

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Identifying disease biomarkers and detecting hazardous, explosive, flammable, and polluting gases and chemicals with extremely sensitive and selective sensor devices remains a challenging and time-consuming research challenge. Due to their exceptional characteristics, semiconducting metal oxides (SMOxs) have received a lot of attention in terms of the development of various types of sensors in recent years. The key performance indicators of SMOx-based sensors are their sensitivity, selectivity, recovery time, and steady response over time. SMOx-based sensors are discussed in this review based on their different properties. Surface properties of the functional material, such as its (nano)structure, morphology, and crystallinity, greatly influence sensor performance. A few examples of the complicated and poorly understood processes involved in SMOx sensing systems are adsorption and chemisorption, charge transfers, and oxygen migration. The future prospects of SMOx-based gas sensors, chemical sensors, and biological sensors are also discussed.

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Qi, Juanjuan, Ke Chen, Yi Xing, Hua Fan, Hewei Zhao, Jie Yang, Lidong Li, et al. "Application of 3D hierarchical monoclinic-type structural Sb-doped WO3 towards NO2 gas detection at low temperature." Nanoscale 10, no. 16 (2018): 7440–50. http://dx.doi.org/10.1039/c8nr01446a.

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Currently, the development of semiconducting metal oxide (SMO)-based gas sensors with innovative modification and three-dimensional (3D) structural designs has become a significant scientific interest due to their potential for addressing key technological challenges.

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Lahlalia, Ayoub, Olivier Le Neel, Ravi Shankar, Siegfried Selberherr, and Lado Filipovic. "Enhanced Sensing Performance of Integrated Gas Sensor Devices." Proceedings 2, no. 13 (December 7, 2018): 1508. http://dx.doi.org/10.3390/proceedings2131508.

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Semiconducting metal oxide (SMO) gas sensors, dedicated to wearable devices were designed, fabricated, and characterized in terms of power consumption, thermal distribution, and sensing capability. The sensors demonstrate a sensitivity down to ppb-level VOC concentrations at a low power consumption of 10.5 mW. To further enhance the baseline stability and sensing response characteristics at low power consumption, a new sensor structure is proposed. The design implements novel aspects in terms of fabrication and microheater geometry, leading to improved sensor performance which enables new applications for SMO gas sensors. In this work, two designs were analyzed using experimental characterization and simulation. The results of the analyses of the two sensors are comparatively reported.

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Li, Zhijie, Hao Li, Zhonglin Wu, Mingkui Wang, Jingting Luo, Hamdi Torun, PingAn Hu, et al. "Advances in designs and mechanisms of semiconducting metal oxide nanostructures for high-precision gas sensors operated at room temperature." Materials Horizons 6, no. 3 (2019): 470–506. http://dx.doi.org/10.1039/c8mh01365a.

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Barsan, N., C. Simion, T. Heine, S. Pokhrel, and U. Weimar. "Modeling of sensing and transduction for p-type semiconducting metal oxide based gas sensors." Journal of Electroceramics 25, no. 1 (June 16, 2009): 11–19. http://dx.doi.org/10.1007/s10832-009-9583-x.

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Hernández, P. Tarttelin, A. J. T. Naik, E. J. Newton, Stephen M. V. Hailes, and I. P. Parkin. "Assessing the potential of metal oxide semiconducting gas sensors for illicit drug detection markers." J. Mater. Chem. A 2, no. 23 (2014): 8952–60. http://dx.doi.org/10.1039/c4ta00357h.

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Bernardini, Sandrine, Florent Pourcin, Nassirou Nambiema, Olivier Margeat, Khalifa Aguir, Christine Videlot-Ackermann, Jörg Ackermann, and Marc Bendahan. "Ammonia Detection at Low Temperature by Tungsten Oxide Nanowires." Proceedings 2, no. 13 (December 10, 2018): 983. http://dx.doi.org/10.3390/proceedings2130983.

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Ammonia detection at low temperatures below 150 °C is attractive to be well suited for flexible substrates in terms of thermal strain and to specific environment not allowing high temperature such as explosive one. In commercial gas sensors, tungsten trioxide is the mostly used semiconducting metal oxide after tin dioxide. We report herein the efficiency of tungsten trioxide nanowires deposited on rigid substrate by drop coating from colloidal solution. This study provides an interesting approach to fabricate ammonia sensors on conformable substrate with significant properties for applications in environmental monitoring devices.

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Zhao, Hongchao, Yanjie Wang, and Yong Zhou. "Accelerating the Gas–Solid Interactions for Conductometric Gas Sensors: Impacting Factors and Improvement Strategies." Materials 16, no. 8 (April 20, 2023): 3249. http://dx.doi.org/10.3390/ma16083249.

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Metal oxide-based conductometric gas sensors (CGS) have showcased a vast application potential in the fields of environmental protection and medical diagnosis due to their unique advantages of high cost-effectiveness, expedient miniaturization, and noninvasive and convenient operation. Of multiple parameters to assess the sensor performance, the reaction speeds, including response and recovery times during the gas–solid interactions, are directly correlated to a timely recognition of the target molecule prior to scheduling the relevant processing solutions and an instant restoration aimed for subsequent repeated exposure tests. In this review, we first take metal oxide semiconductors (MOSs) as the case study and conclude the impact of the semiconducting type as well as the grain size and morphology of MOSs on the reaction speeds of related gas sensors. Second, various improvement strategies, primarily including external stimulus (heat and photons), morphological and structural regulation, element doping, and composite engineering, are successively introduced in detail. Finally, challenges and perspectives are proposed so as to provide the design references for future high-performance CGS featuring swift detection and regeneration.

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Rahbarpour, S., S. Sajed, and H. Ghafoorifard. "Temperature Dependence of Responses in Metal Oxide Gas Sensors." Key Engineering Materials 644 (May 2015): 181–84. http://dx.doi.org/10.4028/www.scientific.net/kem.644.181.

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Selecting an optimum operating temperature for metal oxide gas sensors is of prime technical importance. Here, the temperature behavior of various kinds of metal oxide gas sensors in response to different levels of reducing contaminants in air is reported. The examined gas sensor samples include a Tin oxide-based resistive gas sensor and home-made diode-type Ag-TiO2-Ti gas sensors. Recorded response vs. temperature curves of all samples represent two different typical features: The responses related to the resistive gas sensor exhibit distinct maximum response at a well defined operating temperature regardless of the target gas concentration level, but the diode type samples demonstrated a continuously rising response as the operating temperature decreased to highly contaminated atmospheres. At low contaminant levels, diode type gas sensors change their behaviour and act similar to resistive gas sensors. Reported results were described by a model based on the gas diffusion theory.

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Choi, Hee-Jung, Soon-Hwan Kwon, Won-Seok Lee, Kwang-Gyun Im, Tae-Hyun Kim, Beom-Rae Noh, Sunghoon Park, Semi Oh, and Kyoung-Kook Kim. "Ultraviolet Photoactivated Room Temperature NO2 Gas Sensor of ZnO Hemitubes and Nanotubes Covered with TiO2 Nanoparticles." Nanomaterials 10, no. 3 (March 4, 2020): 462. http://dx.doi.org/10.3390/nano10030462.

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Prolonged exposure to NO2 can cause lung tissue inflammation, bronchiolitis fibrosa obliterans, and silo filler’s disease. In recent years, nanostructured semiconducting metal oxides have been widely used to fabricate gas sensors because of their unique structure and surface-to-volume ratio compared to layered materials. In particular, the different morphologies of ZnO-based nanostructures significantly affect the detection property of NO2 gas sensors. However, because of the large interaction energy of chemisorption (1–10 eV), metal oxide-based gas sensors are typically operated above 100 °C, overcoming the energy limits to attain high sensitivity and fast reaction. High operating temperature negatively affects the reliability and durability of semiconductor-based sensors; at high temperature, the diffusion and sintering effects at the metal oxide grain boundaries are major factors causing undesirable long-term drift problems and preventing stability improvements. Therefore, we demonstrate NO2 gas sensors consisting of ZnO hemitubes (HTs) and nanotubes (NTs) covered with TiO2 nanoparticles (NPs). To operate the gas sensor at room temperature (RT), we measured the gas-sensing properties with ultraviolet illumination onto the active region of the gas sensor for photoactivation instead of conventional thermal activation by heating. The performance of these gas sensors was enhanced by the change of barrier potential at the ZnO/TiO2 interfaces, and their depletion layer was expanded by the NPs formation. The gas sensor based on ZnO HTs showed 1.2 times higher detection property than those consisting of ZnO NTs at the 25 ppm NO2 gas.

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Singh, Ravi Chand, Manmeet Pal Singh, and Hardev Singh Virk. "Applications of Nanostructured Materials as Gas Sensors." Solid State Phenomena 201 (May 2013): 131–58. http://dx.doi.org/10.4028/www.scientific.net/ssp.201.131.

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Gas detection instruments are increasingly needed for industrial health and safety, environmental monitoring, and process control. To meet this demand, considerable research into new sensors is underway, including efforts to enhance the performance of traditional devices, such as resistive metal oxide sensors, through nanoengineering. The resistance of semiconductors is affected by the gaseous ambient. The semiconducting metal oxides based gas sensors exploit this phenomenon. Physical chemistry of solid metal surfaces plays a dominant role in controlling the gas sensing characteristics. Metal oxide sensors have been utilized for several decades for low-cost detection of combustible and toxic gases. Recent advances in nanomaterials provide the opportunity to dramatically increase the response of these materials, as their performance is directly related to exposed surface volume. Proper control of grain size remains a key challenge for high sensor performance. Nanoparticles of SnO2have been synthesized through chemical route at 5, 25 and 50°C. The synthesized particles were sintered at 400, 600 and 800°C and their structural and morphological analysis was carried out using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The reaction temperature is found to be playing a critical role in controlling nanostructure sizes as well as agglomeration. It has been observed that particle synthesized at 5 and 50°C are smaller and less agglomerated as compared to the particles prepared at 25°C. The studies revealed that particle size and agglomeration increases with increase in sintering temperature. Thick films gas sensors were fabricated using synthesized tin dioxide powder and sensing response of all the sensors to ethanol vapors was investigated at different temperatures and concentrations. The investigations revealed that sensing response of SnO2nanoparticles is size dependent and smaller particles display higher sensitivity. Table of Contents

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Mirzaei, Hamed, Milad Ramezankhani, Emily Earl, Nishat Tasnim, Abbas S. Milani, and Mina Hoorfar. "Investigation of a Sparse Autoencoder-Based Feature Transfer Learning Framework for Hydrogen Monitoring Using Microfluidic Olfaction Detectors." Sensors 22, no. 20 (October 11, 2022): 7696. http://dx.doi.org/10.3390/s22207696.

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Alternative fuel sources, such as hydrogen-enriched natural gas (HENG), are highly sought after by governments globally for lowering carbon emissions. Consequently, the recognition of hydrogen as a valuable zero-emission energy carrier has increased, resulting in many countries attempting to enrich natural gas with hydrogen; however, there are rising concerns over the safe use, storage, and transport of H2 due to its characteristics such as flammability, combustion, and explosivity at low concentrations (4 vol%), requiring highly sensitive and selective sensors for safety monitoring. Microfluidic-based metal–oxide–semiconducting (MOS) gas sensors are strong tools for detecting lower levels of natural gas elements; however, their working mechanism results in a lack of real-time analysis techniques to identify the exact concentration of the present gases. Current advanced machine learning models, such as deep learning, require large datasets for training. Moreover, such models perform poorly in data distribution shifts such as instrumental variation. To address this problem, we proposed a Sparse Autoencoder-based Transfer Learning (SAE-TL) framework for estimating the hydrogen gas concentration in HENG mixtures using limited datasets from a 3D printed microfluidic detector coupled with two commercial MOS sensors. Our framework detects concentrations of simulated HENG based on time-series data collected from a cost-effective microfluidic-based detector. This modular gas detector houses metal–oxide–semiconducting (MOS) gas sensors in a microchannel with coated walls, which provides selectivity based on the diffusion pace of different gases. We achieve a dominant performance with the SAE-TL framework compared to typical ML models (94% R-squared). The framework is implementable in real-world applications for fast adaptation of the predictive models to new types of MOS sensor responses.

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Zhou, Qu, Wei Gen Chen, and Shu Di Peng. "Structure and Acetylene Sensing Behavior of Zinc Oxide Nanowires Based Gas Sensor." Advanced Materials Research 971-973 (June 2014): 165–69. http://dx.doi.org/10.4028/www.scientific.net/amr.971-973.165.

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Low-dimensional semiconducting metal oxide nanostructures have gained great interest for developing high performance chemical gas sensors. In this study, we successfully synthesized quasi one-dimensional zinc oxide nanowires via a simple and facile hydrothermal process with zinc acetate dihydrate as precursor and polyethylene glycol as surfactant. The crystalline structures and microstructures of the as prepared samples were investigated by X-ray powder diffraction and field emission scanning electron microscopy, and a possible growth process was discussed in detail. Moreover, thick film gas sensor was fabricated with the as prepared nanowires and its sensing properties to acetylene gas, an important fault characteristic gases dissolved in oil-filled power equipments was measured.

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Haidry, A. A., N. Kind, and B. Saruhan. "Investigating the influence of Al-doping and background humidity on NO<sub>2</sub> sensing characteristics of magnetron-sputtered SnO<sub>2</sub> sensors." Journal of Sensors and Sensor Systems 4, no. 2 (August 31, 2015): 271–80. http://dx.doi.org/10.5194/jsss-4-271-2015.

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Abstract. Elevated temperatures and humidity contents affect response, lifetime and stability of metal-oxide gas sensors. Remarkable efforts are being made to improve the sensing characteristics of metal-oxide-based sensors operating under such conditions. Having versatile semiconducting properties, SnO2 is prominently used for gas sensing applications. The aim of the present work is to demonstrate the capability of the Al-doped SnO2 layer as NO2 selective gas sensor working at high temperatures under the presence of humidity. Undoped SnO2 and Al-doped SnO2 (3 at. % Al) layers were prepared by the radio frequency (r.f.) reactive magnetron sputtering technique, having an average thickness of 2.5 μm. The sensor response of Al-doped SnO2 samples was reduced in the presence of background synthetic air. Moreover, under dry argon conditions, Al doping contributes to obtain a stable signal and to lower cross-sensitivity to CO in the gas mixtures of CO + NO2 at temperatures of 500 and 600 °C. The Al-doped SnO2 sensors exhibit excellent chemical stability and sensitivity towards NO2 gas at the temperature range of 400–600 °C under a humid environment. The sensors also showed satisfactory response (τres = 1.73 min) and recovery (τrec = 2.7 min) towards 50 ppm NO2 in the presence of 10 % RH at 600 °C.

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Hammer, Christof, Johannes Warmer, Sebastian Sporrer, Peter Kaul, Ronald Thoelen, and Norbert Jung. "A Compact, Reliable and Efficient 16 Channel Power Supply for the Automated Screening of Semiconducting Metal Oxide Gas Sensors." Electronics 8, no. 8 (August 9, 2019): 882. http://dx.doi.org/10.3390/electronics8080882.

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The choice of suitable semiconducting metal oxide (MOX) gas sensors for the detection of a specific gas or gas mixture is time-consuming since the sensor’s sensitivity needs to be characterized at multiple temperatures to find its optimal operating conditions. To obtain reliable measurement results, it is very important that the power for the sensor’s integrated heater is stable, regulated and error-free (or error-tolerant). Especially the error-free requirement can be only be achieved if the power supply implements failure-avoiding and failure-detection methods. The biggest challenge is deriving multiple different voltages from a common supply in an efficient way while keeping the system as small and lightweight as possible. This work presents a reliable, compact, embedded system that addresses the power supply requirements for fully automated simultaneous sensor characterization for up to 16 sensors at multiple temperatures. The system implements efficient (avg. 83.3% efficiency) voltage conversion with low ripple output (<32 mV) and supports static or temperature-cycled heating modes. Voltage and current of each channel are constantly monitored and regulated to guarantee reliable operation. To evaluate the proposed design, 16 sensors were screened. The results are shown in the experimental part of this work.

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Tsuruta, Akihiro, Takafumi Akamatsu, Kojiro Naito, Takayoshi Hirai, Seiichiro Murase, and Yoshitake Masuda. "Gas Sensing Properties of High-Purity Semiconducting Single-Walled Carbon Nanotubes for NH₃, H₂, and NO." ECS Journal of Solid State Science and Technology 10, no. 12 (December 1, 2021): 121004. http://dx.doi.org/10.1149/2162-8777/ac4218.

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Gas sensors are advantageous as they can be applied in various fields. The metal-oxide semiconductor gas sensor is the most widely used gas sensor. In this study, the gas-sensing properties of high-purity semiconducting single-walled carbon nanotubes (SWCNTs), which behave as p-type semiconductors, are analyzed at temperatures of 50, 100, and 200 °C for NH3, H2, and NO at various O2 concentrations. The SWCNTs are separated from a mixture of metallic and semiconducting SWCNTs based on the agarose gel column chromatography. The SWCNT gas sensor responds to all the gases in 20% O2, and the gas selectivity to NH3 and H2 is controlled by the operating temperature. NO transforms to NO2 in the presence of O2 and decreases the resistance of the sensor as an oxidizing gas. The sensor can detect NH3, H2, and NO without O2. Along with the good conductivity of the SWCNTs, the good conductive paths between the SWCNTs through the semiconducting polymer dispersant reduce the noise of the sensor resistance and enable the detection of small changes in the resistance to minimal gas concentration.

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Pugh, David C., and Ivan P. Parkin. "Zeolite Modified Vanadium Pentoxide Sensors for the Selective Detection of Volatile Organic Compounds." MRS Advances 1, no. 49 (2016): 3349–54. http://dx.doi.org/10.1557/adv.2016.554.

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ABSTRACTExposure to volatile organic compounds can lead to asphyxiation, pneumonia like conditions, comas, seizures and irreversible lung, kidney and central nervous system damage. Volatile organics are additionally extremely flammable and explosive, making their early detection in the immediate environment increasingly important. Metal oxide semiconductor (MOS) gas sensors present a potential technology to detect such gases.Metal oxide semiconducting (MOS) gas sensors represent a cheap, robust and sensitive technology for detecting volatile organic compounds. An array of five thick film MOS gas sensors was fabricated, based on vanadium pentoxide inks. Production took place using a commercially available screen printer, a 3 x 3 mm alumina substrate containing interdigitated electrodes and a platinum heater track. V2O5inks were modified using zeolite beta, zeolite Y, mordenite & ZSM5 admixtures. Sensors were exposed to three common reducing gases, namely acetone, ethanol, and toluene, and a machine learning technique was applied to differentiate between the different gases. Sensors produced strong responses to all gases. Zeolite modified sensors were found to increase the responsiveness of the sensors compared to umodified V2O5in a number of cases. Machine learning techniques were incorporated to test the selectivity of the sensors. A high level of accuracy was achieved in determining the class of gas observed.

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Hammer, Christof, Johannes Warmer, Stephan Maurer, Peter Kaul, Ronald Thoelen, and Norbert Jung. "A Compact 16 Channel Embedded System with High Dynamic Range Readout and Heater Management for Semiconducting Metal Oxide Gas Sensors." Electronics 9, no. 11 (November 5, 2020): 1855. http://dx.doi.org/10.3390/electronics9111855.

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The simultaneous operation of multiple different semiconducting metal oxide (MOX) gas sensors is demanding for the readout circuitry. The challenge results from the strongly varying signal intensities of the various sensor types to the target gas. While some sensors change their resistance only slightly, other types can react with a resistive change over a range of several decades. Therefore, a suitable readout circuit has to be able to capture all these resistive variations, requiring it to have a very large dynamic range. This work presents a compact embedded system that provides a full, high range input interface (readout and heater management) for MOX sensor operation. The system is modular and consists of a central mainboard that holds up to eight sensor-modules, each capable of supporting up to two MOX sensors, therefore supporting a total maximum of 16 different sensors. Its wide input range is archived using the resistance-to-time measurement method. The system is solely built with commercial off-the-shelf components and tested over a range spanning from 100 Ω to 5 GΩ (9.7 decades) with an average measurement error of 0.27% and a maximum error of 2.11%. The heater management uses a well-tested power-circuit and supports multiple modes of operation, hence enabling the system to be used in highly automated measurement applications. The experimental part of this work presents the results of an exemplary screening of 16 sensors, which was performed to evaluate the system’s performance.

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Ghosal, Suman Ghosal, Swati Dey, Partha Pratim Chattopadhyay, Shubhabrata Datta, and Partha Bhattacharyya. "Designing optimized ternary catalytic alloy electrode for efficiency improvement of semiconductor gas sensors using a machine learning approach." Decision Making: Applications in Management and Engineering 4, no. 2 (October 15, 2021): 126–39. http://dx.doi.org/10.31181/dmame210402126g.

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Catalytic noble metal (s) or its alloy (s) has long been used as the electrode material to enhance the sensing performance of the semiconducting oxide based gas sensors. In the present paper, design of optimized ternary metal alloy electrode, while the database is in pure or binary alloy compositions, using a machine learning methodology is reported for detection of CH4 gas as a test case. Pure noble metals or their binary alloys as the electrode on the semiconducting ZnO sensing layer were investigated by the earlier researchers to enhance the sensitivity towards CH4. Based on those research findings, an artificial neural network (ANN) models were developed considering the three main features of the gas sensor devices, viz. response magnitude, response time and recovery time as a function of ZnO particle size and the composition of the catalytic alloy. A novel methodology was introduced by using ANN models considered for optimized ternary alloy with enriched presentation through the multi-objective genetic algorithm (GA) wherever the generated pareto front was used. The prescriptive data analytics methodology seems to offer more or less convinced evidences for future experimental studies.

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Galstyan, Vardan, Manohar Bhandari, Veronica Sberveglieri, Giorgio Sberveglieri, and Elisabetta Comini. "Metal Oxide Nanostructures in Food Applications: Quality Control and Packaging." Chemosensors 6, no. 2 (April 14, 2018): 16. http://dx.doi.org/10.3390/chemosensors6020016.

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Metal oxide materials have been applied in different fields due to their excellent functional properties. Metal oxides nanostructuration, preparation with the various morphologies, and their coupling with other structures enhance the unique properties of the materials and open new perspectives for their application in the food industry. Chemical gas sensors that are based on semiconducting metal oxide materials can detect the presence of toxins and volatile organic compounds that are produced in food products due to their spoilage and hazardous processes that may take place during the food aging and transportation. Metal oxide nanomaterials can be used in food processing, packaging, and the preservation industry as well. Moreover, the metal oxide-based nanocomposite structures can provide many advantageous features to the final food packaging material, such as antimicrobial activity, enzyme immobilization, oxygen scavenging, mechanical strength, increasing the stability and the shelf life of food, and securing the food against humidity, temperature, and other physiological factors. In this paper, we review the most recent achievements on the synthesis of metal oxide-based nanostructures and their applications in food quality monitoring and active and intelligent packaging.

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Kolmakov, Andrei, Xihong Chen, and Martin Moskovits. "Functionalizing Nanowires with Catalytic Nanoparticles for Gas Sensing Application." Journal of Nanoscience and Nanotechnology 8, no. 1 (January 1, 2008): 111–21. http://dx.doi.org/10.1166/jnn.2008.n10.

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Metal oxide semiconducting nanowires are among the most promising materials systems for use as conductometric gas sensors. These systems function by converting surface chemical processes, often catalytic processes, into observable conductance variations in the nanowire. The surface properties, and hence the sensing properties of these devices can be altered dramatically improving the sensitivity and selectivity, by the deposition of catalytic metal nanoparticles on the nanowire's surface. This leads not only to promising sensor strategies but to a route for understanding some of the fundamental science occurring on these nanoparticles and at the metal/nanowire junction. In particular studying these systems can lead to a better understanding of the influence of the catalyst particle on the electronic structure of the nanowire and its electron transport. This report surveys results obtained so far in this area. In particular, the comparative sensing performance of single quasi-1D chemiresistors (i.e., nanowires or nanobelts) before and after surface decoration with noble metal catalyst particles show significant improvement in sensitivity toward oxidizing and reducing gases. Moreover, one finds that the sensing mechanism can depend dramatically on the degree of metal coverage of the nanowire.

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Potyrailo, Radislav A., Brian Scherer, Baokai Cheng, Majid Nayeri, Shiyao Shan, Janell Crowder, Richard St-Pierre, Joleyn Brewer, and Renner Ruffalo. "First-Order Individual Gas Sensors as Next Generation Reliable Analytical Instruments." Applied Spectroscopy 77, no. 8 (August 2023): 860–72. http://dx.doi.org/10.1177/00037028231186821.

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It is conventionally expected that the performance of existing gas sensors may degrade in the field compared to laboratory conditions because (i) a sensor may lose its accuracy in the presence of chemical interferences and (ii) variations of ambient conditions over time may induce sensor-response fluctuations (i.e., drift). Breaking this status quo in poor sensor performance requires understanding the origins of design principles of existing sensors and bringing new principles to sensor designs. Existing gas sensors are single-output (e.g., resistance, electrical current, light intensity, etc.) sensors, also known as zero-order sensors (Karl Booksh and Bruce R. Kowalski, Analytical Chemistry, DOI: 10.1021/ac00087a718). Any zero-order sensor is undesirably affected by variable chemical background and sensor drift that cannot be distinguished from the response to an analyte. To address these limitations, we are developing multivariable gas sensors with independent responses, which are first-order analytical instruments. Here, we demonstrate self-correction against drift in two types of first-order gas sensors that operate in different portions of the electromagnetic spectrum. Our radiofrequency sensors utilize dielectric excitation of semiconducting metal oxide materials on the shoulder of their dielectric relaxation peak and achieve self-correction of the baseline drift by operation at several frequencies. Our photonic sensors utilize nanostructured sensing materials inspired by Morpho butterflies and achieve self-correction of the baseline drift by operation at several wavelengths. These principles of self-correction for drift effects in first-order sensors open opportunities for diverse emerging monitoring applications that cannot afford frequent periodic maintenance that is typical of traditional analytical instruments.

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Kulkarni, Narasimha, M. C. Navindagi, M. V. S. Murali Krishna, and Shashikant Kushnoore. "Green Mediated Synthesis of Macroporous Hierarchical CeO2 Nanoparticles using Mimosa pudica Leaf Extract for Humidity Sensing Application." Asian Journal of Chemistry 33, no. 6 (2021): 1357–62. http://dx.doi.org/10.14233/ajchem.2021.23190.

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Metal oxide nanoparticles are popular candidates for chemiresistive sensors application. Cerium oxide (CeO2) based semiconducting gas sensors have gained rapid interest in recent years. In this study, an environment-friendly green synthesis approach was employed for the synthesis of macroporous CeO2 nanoparticles using Mimosa pudica leaf extract. Later the performance of CeO2 nanoparticles for humidity sensor is demonstrated. X-ray diffraction studies revealed the cubic fluorite crystal structure with no impurities, scanning electron microscopy analysis revealed the macroporous morphology of CeO2 hierarchical nanoparticles. Humidity sensing properties were studied using interdigitated electrode coated with CeO2 nanoparticles. The results showed the sensing response of 0.5 times for 10% RH (relative humidity) and seven times for 90% RH. The response and recovery times were found to be as low as 12 s and 15 s, respectively. The experimental results provided an environment-friendly approach for the synthesis of CeO2 particles and revealed promising results in humidity sensing application.

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Liang, Xi Feng, and Li Hao Liu. "Design on the Amplifier Circuit of Metal-Oxide Semiconductor Gas-Sensitive Sensor." Applied Mechanics and Materials 220-223 (November 2012): 1939–42. http://dx.doi.org/10.4028/www.scientific.net/amm.220-223.1939.

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Metal-oxide semiconductor gas-sensitive sensors have various advantages as the basic devices of gas detection systems, such as high sensitivity, fast responsibility and low cost, etc. They are widely applied to many fields. Amplifier circuit is an important section of gas detection system. A new type of amplifier circuit including a three-stage operational amplifier was designed in the paper which can effectively eliminate the influence of the follow-up circuit on the sensor output. Theory analysis and experimental simulations were performed. The results show that the output voltage signals have a linear relation with the concentrations of the detected gas.

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Hu, Ying, Ooi Kiang Tan, and Weiguang Zhu. "Nanosized Metal-Oxide Semiconducting $\hbox{SrTi}_{1 \pm x}\hbox{O}_{3 - \delta}$ Oxygen Gas Sensors for Low-Temperature Application." IEEE Sensors Journal 6, no. 6 (December 2006): 1389–94. http://dx.doi.org/10.1109/jsen.2006.884449.

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Koli, Prashant Bhimrao, Kailas Haribhau Kapadnis, Uday Gangadhar Deshpande, Balaji pandurang More, and Umesh Jagannath Tupe. "Sol-Gel Fabricated Transition Metal Cr3+, Co2+ Doped Lanthanum Ferric Oxide (LFO-LaFeO3) Thin Film Sensors for the Detection of Toxic, Flammable Gases: A Comparative Study." Material Science Research India 17, Issue 1 (April 25, 2020): 70–83. http://dx.doi.org/10.13005/msri/170110.

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In this investigation we are reporting the rapid preparation of Perovskite LaFeO3 thin films prepared by sol-gel synthesis followed by spin coating method. The structural properties of the spin coated LaFeO3 thin films measured by X-ray Diffractometer which confirms the formation of monophasic, orthorhombic, Perovskite LaFeO3 material. The morphological features of the films were explore by the ease of scanning electron microscopy, where the crystalline LaFeO3 nanoparticles were observed. Energy dispersive spectroscopy was utilized for the determination of elemental composition. The electrical properties were carried out to confirm the typical semiconducting behaviour of LaFeO3 p- type semiconductor. The thin films were subjected for gas sensing study, the material was found to be very efficient gas sensors for LPG, petrol vapour, CO2, methanol, ethanol, acetone gases. The main object was to discuss comparative study, means, what changes in parameters may be observed due to doping elements. Here undoped LFO sensor showed excellent sensitivity to methanol vapours, while doped LFO sensors found to very sensitive for petrol vapours. The enhanced sensitivity by doped LFO may attributed to increase surface area due to dopants.While all parameter essential for effective sensor were investigated in detail like, response recovery, reusability, selectivity of both the sensors.

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Wei, Huijie, Huiyan Zhang, Bing Song, Kaiping Yuan, Hongbin Xiao, Yunyi Cao, and Qi Cao. "Metal–Organic Framework (MOF) Derivatives as Promising Chemiresistive Gas Sensing Materials: A Review." International Journal of Environmental Research and Public Health 20, no. 5 (March 1, 2023): 4388. http://dx.doi.org/10.3390/ijerph20054388.

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The emission of harmful gases has seriously exceeded relative standards with the rapid development of modern industry, which has shown various negative impacts on human health and the natural environment. Recently, metal–organic frameworks (MOFs)-based materials have been widely used as chemiresistive gas sensing materials for the sensitive detection and monitoring of harmful gases such as NOx, H2S, and many volatile organic compounds (VOCs). In particular, the derivatives of MOFs, which are usually semiconducting metal oxides and oxide–carbon composites, hold great potential to prompt the surface reactions with analytes and thus output amplified resistance changing signals of the chemiresistors, due to their high specific surface areas, versatile structural tunability, diversified surface architectures, as well as their superior selectivity. In this review, we introduce the recent progress in applying sophisticated MOFs-derived materials for chemiresistive gas sensors, with specific emphasis placed on the synthesis and structural regulation of the MOF derivatives, and the promoted surface reaction mechanisms between MOF derivatives and gas analytes. Furthermore, the practical application of MOF derivatives for chemiresistive sensing of NO2, H2S, and typical VOCs (e.g., acetone and ethanol) has been discussed in detail.

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Zhou, Hui, Kai Xu, Nam Ha, Yinfen Cheng, Rui Ou, Qijie Ma, Yihong Hu, et al. "Reversible Room Temperature H2 Gas Sensing Based on Self-Assembled Cobalt Oxysulfide." Sensors 22, no. 1 (December 31, 2021): 303. http://dx.doi.org/10.3390/s22010303.

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Reversible H2 gas sensing at room temperature has been highly desirable given the booming of the Internet of Things (IoT), zero-emission vehicles, and fuel cell technologies. Conventional metal oxide-based semiconducting gas sensors have been considered as suitable candidates given their low-cost, high sensitivity, and long stability. However, the dominant sensing mechanism is based on the chemisorption of gas molecules which requires elevated temperatures to activate the catalytic reaction of target gas molecules with chemisorbed O, leaving the drawbacks of high-power consumption and poor selectivity. In this work, we introduce an alternative candidate of cobalt oxysulfide derived from the calcination of self-assembled cobalt sulfide micro-cages. It is found that the majority of S atoms are replaced by O in cobalt oxysulfide, transforming the crystal structure to tetragonal coordination and slightly expanding the optical bandgap energy. The H2 gas sensing performances of cobalt oxysulfide are fully reversible at room temperature, demonstrating peculiar p-type gas responses with a magnitude of 15% for 1% H2 and a high degree of selectivity over CH4, NO2, and CO2. Such excellent performances are possibly ascribed to the physisorption dominating the gas–matter interaction. This work demonstrates the great potentials of transition metal oxysulfide compounds for room-temperature fully reversible gas sensing.

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Yuliarto, Brian, Gilang Gumilar, and Ni Luh Wulan Septiani. "SnO2Nanostructure as Pollutant Gas Sensors: Synthesis, Sensing Performances, and Mechanism." Advances in Materials Science and Engineering 2015 (2015): 1–14. http://dx.doi.org/10.1155/2015/694823.

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A significant amount of pollutants is produced from factories and motor vehicles in the form of gas. Their negative impact on the environment is well known; therefore detection with effective gas sensors is important as part of pollution prevention efforts. Gas sensors use a metal oxide semiconductor, specifically SnO2nanostructures. This semiconductor is interesting and worthy of further investigation because of its many uses, for example, as lithium battery electrode, energy storage, catalyst, and transistor, and has potential as a gas sensor. In addition, there has to be a discussion of the use of SnO2as a pollutant gas sensor especially for waste products such as CO, CO2, SO2, and NOx. In this paper, the development of the fabrication of SnO2nanostructures synthesis will be described as it relates to the performances as pollutant gas sensors. In addition, the functionalization of SnO2as a gas sensor is extensively discussed with respect to the theory of gas adsorption, the surface features of SnO2, the band gap theory, and electron transfer.

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Chaudhary, Dinesh Kumar, Yogesh Singh Maharjan, Sharmila Pradhan Amatya, Shankar Prasad Shrestha, Rajendra Parajuli, Pitamber Shrestha, and Leela Pradhan Joshi. "Sensing Characteristics of ZnO Nanoparticle Film towards Acetone." Journal of Institute of Science and Technology 27, no. 1 (June 30, 2022): 135–40. http://dx.doi.org/10.3126/jist.v27i1.40866.

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Over the past few decades, nanomaterials of metal oxide such as zinc oxide (ZnO) have been significantly researched for sensing various toxic gases like ethanol, acetone and ammonia. The sensing performance of semiconducting materials depends primarily on their surface structure and the interaction behavior with target gas molecules. The surface quality of ZnO is highly influenced by deposition methods. Although several ZnO surfaces have been rigorously studied for detecting gas leakages, it still possesses drawbacks such as high operating temperature, slow response and recovery times. Henceforth, this investigation was carried out to resolve these issues in the fabrication of future ZnO-based gas sensors. In this work, we report the major findings of the ZnO-based nanoparticle film gas sensor prepared by a doctor blade method to gain insight towards detecting various concentrations of acetone gas at different temperatures. The XRD and FTIR results confirmed the phase purity of ZnO. The results showed the highest response ratio of 25.697 0.012 at 285 oC with an exposure of 800 ppm of acetone along with the quick response and recovery times of 39 sec and 79 sec, respectively. This operating temperature was found to be lower than the reported value for a similar system than that prepared via different methods.

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Meng, Fan-Jian, Rui-Feng Xin, and Shan-Xin Li. "Metal Oxide Heterostructures for Improving Gas Sensing Properties: A Review." Materials 16, no. 1 (December 27, 2022): 263. http://dx.doi.org/10.3390/ma16010263.

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Metal oxide semiconductor gas sensors are widely used to detect toxic and inflammable gases in industrial production and daily life. The main research hotspot in this field is the synthesis of gas sensing materials. Previous studies have shown that incorporating two or more metal oxides to form a heterojunction interface can exhibit superior gas sensing performance in response and selectivity compared with single phase. This review focuses on mainly the synthesis methods and gas sensing mechanisms of metal oxide heterostructures. A significant number of heterostructures with different morphologies and shapes have been fabricated, which exhibit specific sensing performance toward a specific target gas. Among these synthesis methods, the hydrothermal method is noteworthy due to the fabrication of diverse structures, such as nanorod-like, nanoflower-like, and hollow sphere structures with enhanced sensing properties. In addition, it should be noted that the combination of different synthesis methods is also an efficient way to obtain metal oxide heterostructures with novel morphologies. Despite advanced methods in the metal oxide semiconductors and nanotechnology field, there are still some new issues which deserve further investigation, such as long-term chemical stability of sensing materials, reproducibility of the fabrication process, and selectivity toward homogeneous gases. Moreover, the gas sensing mechanism of metal oxide heterostructures is controversial. It should be clarified so as to further integrate laboratory theory research with practical exploitation.

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C, Manjunatha, Ajit Khosla, R. Hari Krishna, P. Vijay Kumar, Sujan Chakraborty, and M. Krishna. "Recent Advances in the Synthesis, Characterization of Pure and Doped NiO Nanostructures for Gas Sensor Applications." ECS Transactions 107, no. 1 (April 24, 2022): 3725–37. http://dx.doi.org/10.1149/10701.3725ecst.

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Nowadays developing the nanomaterials for the sensors capable of sensing at low temperature is given prime importance. In line with this review describes the latest investigations on the effect of metal ion doping on nickel oxide (NiO) sensor capabilities towards various gases. NiO is used as base material of the sensor because of its p-type semiconducting behaviors and its long term stability. Transition metals like Fe, W, Cu, Sn, Nb, In, Ti, and Zn are used as dopants because of their good thermal and electrical conductivity. In this short review article, various synthesis approaches to prepare doped NiO nanostructures and their structural feature are discussed. The development of a sensor device using doped NiO nanostructures and investigation of its sensing property for various gases such as xylene, methane, ethanol, butanol, NO2, etc. are discussed in detail. At the end, all the sensing results were correlated and proposed the suitable conditions to develop the potential doped nanoscaled NiO for better sensor applications.

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Pakiyaraj, K., and V. Kirthika. "Annealing Effect on Nanocrystalline SnO2 Thin Films Prepared by Spray Pyrolysis Technique." Journal of Nanoscience and Technology 7, no. 3 (December 13, 2021): 949–51. http://dx.doi.org/10.30799/jnst.330.21070301.

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In recent years, a transparent conducting oxide (TCO) SnO2 semiconductor have gained considerable attention due to their potential application in gas sensors. More number of studies on TCO oxide have focused on the semiconducting metal oxides in which an intensive argument is that the transparent semiconductors. The SnO2 thin films were deposited at 400 °C and then annealed at 500 °C and 600 °C and its structural, optical and electrical properties were characterized. The doping stoichiometric ratio was maintained as 4% and the resulting solution was sprayed on glass substrate which was kept at nozzle distance of 25 cm and the spray rate was 10 mL/min. The prepared pure SnO2 thin films have been characterized by different methods such as XRD, FESEM, UV-Vis NIR and EDAX analyses. It was found that the nanocrystalline SnO2 grains possesses structural features of the tetragonal rutile structure. Hence the prepared thin films are justified to be nanocrystalline and also the mean crystalline size decreased with respect to annealing temperature.

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Tarttelin Hernández, P., S. M. V. Hailes, and I. P. Parkin. "Hydrocarbon detection with metal oxide semiconducting gas sensors modified by overlayer or admixture of zeolites Na-A, H-Y and H-ZSM-5." Sensors and Actuators B: Chemical 242 (April 2017): 1281–95. http://dx.doi.org/10.1016/j.snb.2016.09.006.

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Zhang, Chunmei, Yalong Jiao, Fengxian Ma, Sri Kasi Matta, Steven Bottle, and Aijun Du. "Free-radical gases on two-dimensional transition-metal disulfides (XS2, X = Mo/W): robust half-metallicity for efficient nitrogen oxide sensors." Beilstein Journal of Nanotechnology 9 (June 5, 2018): 1641–46. http://dx.doi.org/10.3762/bjnano.9.156.

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The detection of single gas molecules is a highly challenging work because it requires sensors with an ultra-high level of sensitivity. By using density functional theory, here we demonstrate that the adsorption of a paramagnetic unpaired free radical gas (NO) on a monolayer of XS2 (X = Mo, W) can trigger the transition from semiconductor to half metal. More precisely, the single-layer XS2 (X = Mo, W) with NO adsorbed on it would behave like a metal in one spin channel while acting as a semiconductor in the other spin orientation. The half-metallicity is robust and independent of the NO concentration. In contrast, no half-metallic feature can be observed after the adsorption of other free radical gases such as NO2. The unique change in electronic properties after the adsorption of NO on transition-metal sulfides highlights an effective strategy to distinguish NO from other gas species by experimentally measuring spin-resolved transmission. Our results also suggest XS2 (X = Mo, W) nanosheets can act as promising nanoscale NO sensors.

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Chakraborthy, Aniket, Sudeep M, Vishal Chaudhary, Manjunatha C, Sujan Chakraborty, and M. Krishna. "Advances and Prospects in Architecting SnO₂ Based Nanosystems for Gas Sensing Applications." ECS Transactions 107, no. 1 (April 24, 2022): 14289–303. http://dx.doi.org/10.1149/10701.14289ecst.

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Currently, the gas sensor market is worth USD 2.33 billion. It is forecasted that the growth of compound annual rate value willing to be 8.7% within the length from 2021 to 2028. The commercial prospects of the semiconducting metal oxide-based gas sensor are limited due to high-temperature operation, higher power consumption, short-term stability, and sensitivity to humidity. Amongst all, tin oxide-based sensors are most commercialized owing to their tunable physicochemical properties. Moreover, the bottlenecks of elevated temperature operation, stability, and selectivity can be catered to by developing its hybrid nanocomposites with other organic and inorganic materials. The multi-interactions, surface functionalization, and formation of heterojunctions in SnO2 nanocomposites enhance their interaction with analyte molecules resulting in excellent sensing performances. This review aims to provide insights into various synthesis strategies to fabricate SnO2 and its hybrid nanocomposites. The advancements in physicochemical properties and structural chemistries are discussed in terms of various spectroscopic analyses. Further, the development in sensor devices using hybrid SnO2 nanoparticles and their sensing properties towards different gasses and VOCs are discussed. This review focuses on studies dealing with low and moderate-temperature gas detection through SnO2 based nanosystems. A comprehensive comparison and correlation of all the mentioned sensing results have been concluded to propose suitable conditions, hybrid SnO2 nanocomposite for superior gas sensing applications.

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Siebert, Leonard, Niklas Wolff, Nicolai Ababii, Maik-Ivo Terasa, Oleg Lupan, Alexander Vahl, Viola Duppel, et al. "Facile fabrication of semiconducting oxide nanostructures by direct ink writing of readily available metal microparticles and their application as low power acetone gas sensors." Nano Energy 70 (April 2020): 104420. http://dx.doi.org/10.1016/j.nanoen.2019.104420.

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Journal articles on the topic 'Semiconducting Metal Oxide Gas Sensors Theory'

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