scholarly journals Fabrication of Lettuce-Like ZnO Gas Sensor with Enhanced H2S Gas Sensitivity

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 145 ◽  
Author(s):  
Ziyang Yu ◽  
Jie Gao ◽  
Longxiao Xu ◽  
Tianyu Liu ◽  
Yueying Liu ◽  
...  
Keyword(s):  
Detection Limit ◽  
Gas Sensor ◽  
Recovery Time ◽  
High Sensitivity ◽  
Fast Response ◽  
Chemical Compositions ◽  
Gas Sensitivity ◽  
Response Characteristics ◽  
One Step ◽  
H2s Detection

In this work, a lettuce-like ZnO gas sensor with high sensitivity for H2S detection was successfully fabricated by a one-step hydrothermal method. Characterization analysis of the phases, crystallinities, morphology, and chemical compositions indicated that lettuce-like ZnO has a lettuce-like microsphere structure composed of wurtzite hexagonal ZnO sheets. A gas sensitivity test of the lettuce-like ZnO showed that the sensor had a high H2S response (113.04 for 100 ppm H2S) and H2S selectivity. The lettuce-like ZnO sensor has fast response characteristics while maintaining high sensitivity, and has a response time as low as 15 seconds and a recovery time of 90 seconds, and the detection limit reaches 1 ppm. The sensitive mechanism of lettuce-like ZnO sensor to H2S is also discussed.

scholarly journals Improved Sensing Capability of Integrated Semiconducting Metal Oxide Gas Sensor Devices

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 374 ◽  
Author(s):  
Ayoub Lahlalia ◽  
Olivier Le Neel ◽  
Ravi Shankar ◽  
Siegfried Selberherr ◽  
Lado Filipovic
Keyword(s):  
Metal Oxide ◽  
Power Consumption ◽  
Low Power ◽  
Gas Sensor ◽  
High Sensitivity ◽  
Fast Response ◽  
Low Power Consumption ◽  
Response Characteristics ◽  
The Impact ◽  
Semiconducting Metal Oxide

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.

Effect of Operating Temperature on Characteristics of Single-Walled Carbon Nanotubes Gas Sensor

2005 ◽  
Vol 486-487 ◽  
pp. 485-488 ◽  
Author(s):  
Hong Quang Nguyen ◽  
Mai Van Trinh ◽  
Jeung Soo Huh
Keyword(s):  
Carbon Nanotubes ◽  
Gas Sensor ◽  
Gas Adsorption ◽  
Operating Temperature ◽  
High Sensitivity ◽  
Single Walled Carbon Nanotubes ◽  
Fast Response ◽  
Carrier Gas ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

The effect of operating temperature on characteristics of single-walled carbon nanotubes (SWNT) based gas sensor was investigated. SWNT-based sensor was fabricated from SWNT powder (Iljin Nanotech, Korea) by screen-printing method. SWNT powder (30 mg, AP grade) was dispersed into 0.78 gram a-terpineol (Aldrich) by ultrasonic vibration for 1 hour then stirred manually for 1 hour to increase adhesion. From this condensed solution, a thick film of SWNT was printed onto alumina substrates. The film then was sintered at 300oC for 2 hours to remove residual impurities. Upon exposure to some gases such as nitrogen, ammonia or nitric oxide, resistance of the sensor dramatically changes due to gas adsorption. In our experiments, SWNT-based sensor was employed to detect NH3 gas in N2 ambience. After saturated of N2, the sensor exposes to NH3 with various concentrations (from 5 ppm to 100 ppm, diluted by N2 as carrier gas). This sensor exhibits a fast response, high sensitivity but slow recovery at room temperature. By heating at high temperature and increasing the flow-rate of carrier gas, NH3 gas desorbs easily and recovery of the sensor improved. The heating also influenced the characteristics of sensors such as response and reproducibility. Other special changes in electric property of SWNT-based sensor caused by heating are also discussed.

Porous ZnO/rGO Nanosheet‐Based NO 2 Gas Sensor with High Sensitivity and ppb‐Level Detection Limit at Room Temperature

2021 ◽  
pp. 2101511
Author(s):  
Ziwei Chen ◽  
Haojie Guo ◽  
Fusheng Zhang ◽  
Xiaowen Li ◽  
Jiabing Yu ◽  
...  
Keyword(s):  
Detection Limit ◽  
Gas Sensor ◽  
Room Temperature ◽  
High Sensitivity

A facile method for preparation of porous nitrogen-doped Ti Ti3C2Tx MXene for highly responsive acetone detection at high temperature

2021 ◽  
pp. 2151043
Author(s):  
Zijing Wang ◽  
Fen Wang ◽  
Angga Hermawan ◽  
Jianfeng Zhu ◽  
Shu Yin
Keyword(s):  
Gas Sensor ◽  
Recovery Time ◽  
Gas Sensing ◽  
Three Dimensional ◽  
Gas Sensitivity ◽  
Nitrogen Doped ◽  
Dimensional Network ◽  
Potential Applications ◽  
Response And Recovery ◽  
Acetone Detection

Porous nitrogen-doped Ti3C2T[Formula: see text] MXene (N-TCT) with a three-dimensional network structure is synthesized via a simple sacrifice template method and then utilized as an acetone gas sensor. By introducing nitrogen atoms as heteroatoms into Ti3C2T[Formula: see text] nanosheets, some defects generate around the doped nitrogen atoms, which can greatly improve the surface hydrophilicity and adsorption capacity of Ti3C2T[Formula: see text] Mxene nanosheets. It resulted in the enhanced gas sensitivity, achieving a response value of about 36 ([Formula: see text]/[Formula: see text] × 100%) and excellent recovery time (9s) at 150[Formula: see text]C. Compared with the pure Ti3C2T[Formula: see text]-based gas sensor (381/92s), the response and recovery time are both obviously improved, and the response value increased by 3.5 times. The gas-sensing mechanism of the porous N-TCT is also discussed in detail. Based on the excellent gas sensitivity of porous N-TCT for highly responsive acetone detection at high temperatures, the strategy of nitrogen-doped two-dimensional nanomaterials can be extended to other nanomaterials to realize their potential applications.

scholarly journals Hydrogen gas sensor based on mesoporous In2O3 with fast response/recovery and ppb level detection limit

2018 ◽  
Vol 43 (50) ◽  
pp. 22746-22755 ◽  
Author(s):  
Zhijie Li ◽  
Shengnan Yan ◽  
Zhonglin Wu ◽  
Hao Li ◽  
Junqiang Wang ◽  
...  
Keyword(s):  
Detection Limit ◽  
Gas Sensor ◽  
Fast Response ◽  
Hydrogen Gas ◽  
Response Recovery

Design of Photoionization Detector Based on the Miniature Gas Chromatography

2013 ◽  
Vol 823 ◽  
pp. 291-295 ◽  
Author(s):  
Shou Chen Chai ◽  
Peng Yang ◽  
Cheng Jia Yang ◽  
Chun Li Cai ◽  
Na Yu
Keyword(s):  
Gas Chromatography ◽  
Detection Limit ◽  
Ionization Chamber ◽  
High Sensitivity ◽  
Fast Response ◽  
Low Detection Limit ◽  
Photoionization Detector ◽  
Key Factor ◽  
The Stability ◽  
Sensitivity Detection

In the space restricted airtight environment that people lives in, detecting harmful gas by miniature gas chromatography is the practical requirement at present, however, PIDs performance is key factor that restrict the application of miniature gas chromatography, the redesign of the detectors gas route in this paper aiming at improve detectors stability observably, and schemed out miniature PID with high sensitivity, low detection limit and fast response. The result of the experiment shows that the detection limit is 0.04ppm, the sensitivity is 101mv/ppm,the stability is 0.04×10-6/24h,meeting the project requirement. Keywords: photoionization detector; ionization chamber; sensitivity; detection limit;

scholarly journals A Novel Type Room Temperature Surface Photovoltage Gas Sensor Device 

2018 ◽  
Author(s):  
Monika Kwoka ◽  
Michal A. Borysiewicz ◽  
Pawel Tomkiewicz ◽  
Anna Piotrowska ◽  
Jacek Szuber
Keyword(s):  
Gas Sensor ◽  
Room Temperature ◽  
Gas Sensing ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Fast Response ◽  
Surface Photovoltage ◽  
Kelvin Probe ◽  
Sensor Device ◽  
Developed Surface

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

scholarly journals Cellulose Nanopaper Cross-Linked Amino Graphene/Polyaniline Sensors to Detect CO2 Gas at Room Temperature

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5215 ◽  
Author(s):  
Hanan Abdali ◽  
Bentolhoda Heli ◽  
Abdellah Ajji
Keyword(s):  
Bacterial Cellulose ◽  
Room Temperature ◽  
Morphological Structure ◽  
High Sensitivity ◽  
Fast Response ◽  
Aniline Monomer ◽  
Resistance Response ◽  
Covalent Interaction ◽  
Response Characteristics ◽  
Carbon Dioxide Co2

A nanocomposite of cross-linked bacterial cellulose–amino graphene/polyaniline (CLBC-AmG/PANI) was synthesized by covalent interaction of amino-functionalized graphene (AmG) AmG and bacterial cellulose (BC) via one step esterification, and then the aniline monomer was grown on the surface of CLBC-AmG through in situ chemical polymerization. The morphological structure and properties of the samples were characterized by using scanning electron microscopy (SEM), and thermal gravimetric analyzer (TGA). The CLBC-AmG/PANI showed good electrical-resistance response toward carbon dioxide (CO2) at room temperature, compared to the BC/PANI nanopaper composites. The CLBC-AmG/PANI sensor possesses high sensitivity and fast response characteristics over CO2 concentrations ranging from 50 to 2000 ppm. This process presents an extremely suitable candidate for developing novel nanomaterials sensors owing to easy fabrication and efficient sensing performance.

A comparative study of electrocatalytic oxidation of glucose on conductive Ni-MOF nanosheet arrays with different ligands

2020 ◽  
Vol 44 (41) ◽  
pp. 17849-17853
Author(s):  
Yanxia Qiao ◽  
Rui Zhang ◽  
Fangyuan He ◽  
Wenli Hu ◽  
Xiaowei Cao ◽  
...  
Keyword(s):  
Detection Limit ◽  
Comparative Study ◽  
Response Time ◽  
Electrocatalytic Oxidation ◽  
Glucose Sensor ◽  
High Sensitivity ◽  
Fast Response ◽  
Serum Samples ◽  
Nanosheet Arrays ◽  
Oxidation Of Glucose

A glucose sensor based on conductive Ni-MOF nanosheet arrays/CC exhibits a fast response time, a low detection limit, a high sensitivity, and it can also be applied for the detection of glucose in human serum samples.

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