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.

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.

Inter-Pulse Spectroscopy Based on Room-Temperature Pulsed Quantum-Cascade Laser for N2O Detection

2011 ◽  
Vol 128-129 ◽  
pp. 607-610
Author(s):  
Min Wang ◽  
Jie Chen ◽  
Niu Liu ◽  
Ya Wang
Keyword(s):  
Absorption Spectrum ◽  
Room Temperature ◽  
Single Point ◽  
High Sensitivity ◽  
Fast Response ◽  
Trace Gas ◽  
High Resolution Spectrum ◽  
Light Sources ◽  
Quantum Cascade ◽  
Pulse Spectroscopy

Mid-infrared lasers are very suitable for high-sensitive trace-gases detection for their wavelengths cover the fundamental absorption lines of most gases. Quantum-cascade (QC) lasers have been demonstrated to be ideal light sources with its special power, tuning and capability of operating in room-temperature. All these merits make it appropriate for the high resolution spectrum analysis. The absorption spectrum monitoring technology based on the QC laser pulsed operating in the room temperature, combining with the strong absorption of the gas molecule in the basic frequency, has become an effective way to monitor the trace gas with the characteristic of high sensitivity, good selectivity and fast response. In this paper, the inter-pulse spectroscopy based on a room-temperature distributed-feedback pulsed QC laser was introduced. Our approach to trace gas monitoring with QC lasers relies on short current pulses which are designed to produce even shorter light pulses. Each pulse corresponds to a single point in a spectrum. The N2O absorption spectrum centered at 2178.2cm-1was also obtained.

Micro Sensor Operating at Room Temperature

2004 ◽  
Vol 828 ◽  
Author(s):  
Song-Kap Duk ◽  
Duk-Dong Lee
Keyword(s):  
Work Function ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Gate Voltage ◽  
Room Temperature ◽  
Film Surface ◽  
High Sensitivity ◽  
Gas Detection ◽  
Pani Film ◽  
Response Characteristics

ABSTRACTIn the study, low power micro gas sensors operated at room temperature for the detection of NH3 and NOx gases are proposed. As candidate material of gas sensor for NH3 gas detection at room temperature, polyaniline(PANi) synthesized by chemical polymerization was selected. And Te(Tellurium) thin film was used for NOx gas detection at room temperature. By using these sensing materials, micro gas sensors for room temperature operation were prepared and measured the response characteristics for NH3 and NOx.In case of PANi sensor, the structure was inverted staggered FET type having advantage of useful one for Lab-On-a-Chip. The operating principle of the sensor is based on the change in work function of PANi film caused by adsorption of gas molecules in air on the film surface. The change in work function was measured indirectly from that in gate voltage of the FET device. The responses to various gases (NH3, CH4, Methanol and CH3CN) were obtained in gate voltage step mode in R.H. 30%. And in case of Te sensor, the sensing material was thermally evaporated on glass substrate. The thickness and annealing temperature were 500 Å −2000 Å and 100 °C −300 °C, respectively. The Te-based micro gas sensor exhibited high sensitivity to NOx and good selectivity against CO and hydro-carbon gases. And by adding Ti to Te film, the sensor has a good selectivity to CO gas.

Studies on the Preparation and Gas Sensing Properties of SnO2 Nanostructures at Room Temperature

2010 ◽  
Vol 93-94 ◽  
pp. 227-230 ◽  
Author(s):  
Kiattisak Noipa ◽  
Supakorn Pukird
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Sno2 Nanoparticles ◽  
High Sensitivity ◽  
Fast Response ◽  
Sno2 Nanostructures ◽  
X Rays ◽  
Sem Images ◽  
Stereo Microscope ◽  
Xrd Patterns

The SnO2 nanostructures have been synthesized by carbon-assisted growth at 800 oC for 3 hours. Using high pure tin powder as the source materials. The synthesized products were investigated by stereo microscope, X-rays diffraction (XRD) and scanning electron microscopy (SEM). XRD patterns show that the prepared products are tetragonal-structures with the lattice constant a = 0.4718 nm and c = 0.3187 nm. SEM images indicate that SnO2 nanowires are about tens of micrometers in length, 80-100 nm in width. The diameter of SnO2 nanoparticles vary from 10 nm to 100 nm. The synthesized products are high sensitivity and fast response time to ethanol gas at room temperature.

H2S DETECTION BY CuO NANOWIRES AT ROOM TEMPERATURE

2011 ◽  
Vol 10 (04n05) ◽  
pp. 733-737
Author(s):  
MANMEET KAUR ◽  
KAILASA GANAPATHI ◽  
NIYANTA DATTA ◽  
K. P. MUTHE ◽  
S. K. GUPTA
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Fast Response ◽  
Oxygen Adsorption ◽  
Initial Increase ◽  
Cuo Nanowires ◽  
Cuo Nanowire ◽  
High Concentrations ◽  
Different Response

Room temperature gas sensing properties of CuO nanowires synthesized by thermal oxidation of copper foils was studied in different configurations: (i) isolated nanowires aligned between two electrodes, (ii) as grown CuO foil consisting of nanowires and (iii) CuO nanowire films. Sensors were studied for response to different gases. Different sensors showed qualitatively different response on exposure to H2S . Isolated nanowires showed high sensitivity, (~200% for 10 ppm of gas) and fast response (30 s) and recovery times (60 s). In these samples, the resistance mainly decreased on exposure to H2S (though a small initial increase was observed). In CuO foils, resistance increased for low concentrations (5–10 ppm) but decreased at high concentrations. In the case of CuO nanowire films, resistance only increased on exposure of H2S (upto 400 ppm). Since CuO is a p-type semiconductor, on exposure to H2S an increase in resistance is expected due to oxygen adsorption related process. Decrease in resistance in some of the sensors was understood in terms of reaction of CuO with H2S resulting in the formation of CuS .

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.

Ultrasensitive room temperature NH3 sensor based on a graphene–polyaniline hybrid loaded on PET thin film

2015 ◽  
Vol 51 (35) ◽  
pp. 7524-7527 ◽  
Author(s):  
Shouli Bai ◽  
Yangbo Zhao ◽  
Jianhua Sun ◽  
Ye Tian ◽  
Ruixian Luo ◽  
...  
Keyword(s):  
Thin Film ◽  
Room Temperature ◽  
Oxidative Polymerization ◽  
High Sensitivity ◽  
Fast Response ◽  
Chemical Oxidative Polymerization ◽  
Nh3 Sensor ◽  
First Time

A room temperature smart NH3 sensor based on rGO–PANI hybrid loading on flexible PET thin film prepared by in situ chemical oxidative polymerization is reported for the first time. The sensor not only exhibits high sensitivity, good selectivity and fast response but also has flexibility, is inexpensive and has wearable characteristics.

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