scholarly journals Semiconductor Metal Oxide Nanoparticles: A Review for the Potential of H2S Gas Sensor Application

2020 ◽  
pp. 199-208
Author(s):  
Zaid Hameed Mahmoud ◽  
Omar Dhaa Abdalstar ◽  
Noor Sabah
Keyword(s):  
Metal Oxide ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Low Cost ◽  
Metal Oxide Nanoparticles ◽  
High Sensitivity ◽  
Modern World ◽  
H2s Gas Sensor ◽  
Work Mechanism ◽  
Semiconductor Metal Oxide

In modern world, gas sensors play important role in many fields of technology used for air pollution, breath analysis, public safety and many others. Gas sensor based semiconductor metal oxide is mostly used in these applications because of low cost, ease-to-use, high sensitivity and lower power consumption. This paper gives an overview about the semiconductor metal oxide and reviews why using it as sensing of gases in electrical applications and then it addresses to the work mechanism of a sensor to sensing H2S gas.

Enhanced selectivity of target gas molecules through a minimal array of gas sensors based on nanoparticle-decorated SWCNTs

The Analyst ◽  
2019 ◽  
Vol 144 (13) ◽  
pp. 4100-4110 ◽  
Author(s):  
Sonia Freddi ◽  
Giovanni Drera ◽  
Stefania Pagliara ◽  
Andrea Goldoni ◽  
Luigi Sangaletti
Keyword(s):  
Metal Oxide ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Metal Oxide Nanoparticles ◽  
Sensor Arrays ◽  
Oxide Nanoparticles ◽  
Gas Molecules ◽  
Enhanced Selectivity ◽  
Gas Sensor Arrays

Layers of CNTs decorated with metal and metal–oxide nanoparticles can be used to develop highly selective gas sensor arrays.

scholarly journals Ultraviolet Photoactivated Room Temperature NO2 Gas Sensor of ZnO Hemitubes and Nanotubes Covered with TiO2 Nanoparticles

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 462 ◽  
Author(s):  
Hee-Jung Choi ◽  
Soon-Hwan Kwon ◽  
Won-Seok Lee ◽  
Kwang-Gyun Im ◽  
Tae-Hyun Kim ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Tio2 Nanoparticles ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Room Temperature ◽  
Prolonged Exposure ◽  
Volume Ratio ◽  
High Sensitivity ◽  
Detection Property ◽  
No2 Gas Sensors

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.

Obtaining Highly Selective Responses from a Bulk Tin Oxide Gas Sensor

2013 ◽  
Vol 543 ◽  
pp. 239-242 ◽  
Author(s):  
Faramarz Hossein-Babaei ◽  
Amir Amini
Keyword(s):  
Gas Sensor ◽  
Gas Sensors ◽  
Tin Oxide ◽  
Low Cost ◽  
High Sensitivity ◽  
Thermal Capacity ◽  
Temperature Modulation ◽  
Custom Made ◽  
Metal Oxide Gas Sensors ◽  
Voltage Spike

Generic gas sensors are commonly used for the detection of different airborne contaminants due to their high sensitivity, long life and low cost, but they generally suffer from the variety of drifts and the lack of selectivity. Different techniques have been developed for selectivity enhancement in metal oxide gas sensors, among which operating temperature modulation is well known. It has been observed that sharp pallet temperature changes provide more analyte-related information. Due to the high thermal capacitance of the device, applying step voltage pulses to a bulk tin oxide gas sensor fails to provide step pallet temperature variations. On the other hand, the low thermal capacity of the custom made microheater gas sensors renders them vulnerable to all kinds of thermal noise and agitations. A novel technique is reported for temperature modulation, which facilitates sharp temperature rises of the gas sensitive pallets in generic gas sensors [. In this technique, a sharp heating voltage spike, considerably surpassing the nominal heating voltage, is applied prior to each heating voltage step. The thermal impact of these spikes is adjusted by controlling v2dt for obtaining the closest variations to the ideal temperature profile. Here, the advantages and effectiveness of the technique are demonstrated by differentiating among iso-butanol, tert-butanol, 1-butanol and 2-butanol contaminations in a wide concentration range in air using only a single generic tin oxide gas sensor.

scholarly journals A silver nanoparticle-anchored UiO-66(Zr) metal–organic framework (MOF)-based capacitive H2S gas sensor

CrystEngComm ◽  
2019 ◽  
Vol 21 (47) ◽  
pp. 7303-7312 ◽  
Author(s):  
Sandeep G. Surya ◽  
Sreenu Bhanoth ◽  
Sanjit M. Majhi ◽  
Yogeshwar D. More ◽  
V. Mani Teja ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Gas Sensor ◽  
Silver Nanoparticle ◽  
Metal Organic Framework ◽  
Metal Oxide Nanoparticles ◽  
Metal Organic Frameworks ◽  
Oxide Nanoparticles ◽  
Enhanced Sensitivity ◽  
H2s Gas Sensor ◽  
Metal Organic

Metal–organic frameworks anchored with metal oxide nanoparticles for the detection of H2S gas with enhanced sensitivity.

scholarly journals Application of an Array of Metal-Oxide Semiconductor Gas Sensors in an Assistant Personal Robot for Early Gas Leak Detection

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 1957 ◽  
Author(s):  
Jordi Palacín ◽  
David Martínez ◽  
Eduard Clotet ◽  
Tomàs Pallejà ◽  
Javier Burgués ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Mobile Robot ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Sensor Array ◽  
Low Cost ◽  
Gas Sensor Array ◽  
Gas Leak ◽  
Detection Capabilities ◽  
Personal Robot

This paper proposes the application of a low-cost gas sensor array in an assistant personal robot (APR) in order to extend the capabilities of the mobile robot as an early gas leak detector for safety purposes. The gas sensor array is composed of 16 low-cost metal-oxide (MOX) gas sensors, which are continuously in operation. The mobile robot was modified to keep the gas sensor array always switched on, even in the case of battery recharge. The gas sensor array provides 16 individual gas measurements and one output that is a cumulative summary of all measurements, used as an overall indicator of a gas concentration change. The results of preliminary experiments were used to train a partial least squares discriminant analysis (PLS-DA) classifier with air, ethanol, and acetone as output classes. Then, the mobile robot gas leak detection capabilities were experimentally evaluated in a public facility, by forcing the evaporation of (1) ethanol, (2) acetone, and (3) ethanol and acetone at different locations. The positive results obtained in different operation conditions over the course of one month confirmed the early detection capabilities of the proposed mobile system. For example, the APR was able to detect a gas leak produced inside a closed room from the external corridor due to small leakages under the door induced by the forced ventilation system of the building.

scholarly journals A Sensitive Resonant Gas Sensor Based on Multimode Excitation of a Buckled Beam

2019 ◽  
Author(s):  
Amal Z. Hajjaj ◽  
Nizar Jaber ◽  
Nouha Alcheikh ◽  
Mohammad I. Younis
Keyword(s):  
Thermal Conductivity ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Low Cost ◽  
High Sensitivity ◽  
Gas Absorption ◽  
Surface Areas ◽  
Resistance Variation ◽  
Long Lifetime ◽  
Alternative Approaches

Abstract The quest for ultra-sensitive low-cost miniaturized gas sensors in the past few decades has sparked interest to seek alternative approaches other than the conventional gas sensors that need large surface areas and special chemicals for functionalization. MEMS thermal conductivity based gas sensors [1, 2] have been shown to be among the promising candidates since they do not rely on gas absorption or chemical reactions. These sensors show long lifetime and great stability compared to conventional gas sensor. The thermal conductivity based gas sensors rely on the resistance variation of the heated structures due to gas exposure [1]. Typical values of resistance changes are less than few percent. Here, we present a thermal conductivity based gas sensor relying on frequency shifts of an electrothermally heated bridge operated near the buckling point, which leads to ultra-high sensitivity.

Metal-oxide based ammonia gas sensors: A review

2020 ◽  
Vol 10 ◽  
Author(s):  
Priya Gupta ◽  
Savita Maurya ◽  
Narendra Kumar Pandey ◽  
Vernica Verma
Keyword(s):  
Metal Oxide ◽  
Metal Oxides ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Review Paper ◽  
Gas Sensing ◽  
Gas Sensitivity ◽  
Ammonia Gas ◽  
Ammonia Sensing ◽  
Ammonia Gas Sensors

: This review paper encompasses a study of metal-oxide and their composite based gas sensors used for the detection of ammonia (NH3) gas. Metal-oxide has come into view as an encouraging choice in the gas sensor industry. This review paper focuses on the ammonia sensing principle of the metal oxides. It also includes various approaches adopted for increasing the gas sensitivity of metal-oxide sensors. Increasing the sensitivity of the ammonia gas sensor includes size effects and doping by metal or other metal oxides which will change the microstructure and morphology of the metal oxides. Different parameters that affect the performances like sensitivity, stability, and selectivity of gas sensors are discussed in this paper. Performances of the most operated metal oxides with strengths and limitations in ammonia gas sensing application are reviewed. The challenges for the development of high sensitive and selective ammonia gas sensor are also discussed.

scholarly journals Sensitive and Low-Power Metal Oxide Gas Sensors with a Low-Cost Microelectromechanical Heater

ACS Omega ◽  
2021 ◽  
Author(s):  
Yulong Chen ◽  
Mingjie Li ◽  
Wenjun Yan ◽  
Xin Zhuang ◽  
Kar Wei Ng ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Low Power ◽  
Gas Sensors ◽  
Low Cost ◽  
Metal Oxide Gas Sensors

scholarly journals Field Study of Metal Oxide Semiconductor Gas Sensors in Temperature Cycled Operation for Selective VOC Monitoring in Indoor Air

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 647
Author(s):  
Tobias Baur ◽  
Johannes Amann ◽  
Caroline Schultealbert ◽  
Andreas Schütze
Keyword(s):  
Air Quality ◽  
Metal Oxide ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Indoor Air ◽  
Ambient Air ◽  
Quantitative Agreement ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
High Temporal Resolution

More and more metal oxide semiconductor (MOS) gas sensors with digital interfaces are entering the market for indoor air quality (IAQ) monitoring. These sensors are intended to measure volatile organic compounds (VOCs) in indoor air, an important air quality factor. However, their standard operating mode often does not make full use of their true capabilities. More sophisticated operation modes, extensive calibration and advanced data evaluation can significantly improve VOC measurements and, furthermore, achieve selective measurements of single gases or at least types of VOCs. This study provides an overview of the potential and limits of MOS gas sensors for IAQ monitoring using temperature cycled operation (TCO), calibration with randomized exposure and data-based models trained with advanced machine learning. After lab calibration, a commercial digital gas sensor with four different gas-sensitive layers was tested in the field over several weeks. In addition to monitoring normal ambient air, release tests were performed with compounds that were included in the lab calibration, but also with additional VOCs. The tests were accompanied by different analytical systems (GC-MS with Tenax sampling, mobile GC-PID and GC-RCP). The results show quantitative agreement between analytical systems and the MOS gas sensor system. The study shows that MOS sensors are highly suitable for determining the overall VOC concentrations with high temporal resolution and, with some restrictions, also for selective measurements of individual components.

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