An indoor light-activated 3D cone-shaped MoS2 bilayer-based NO gas sensor with PPb-level detection at room-temperature

Effective monitoring of hazardous gases at room-temperature is extremely indispensable in the “Internet of things” application; however, developing bifunctional gas sensors for the advanced sensing platform still remains a challenge....

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Ag Continuous Doped SnO2 Sensor Selective to Co2 in Presence of Ethanol at Room Temperature

Annals of West University of Timisoara - Physics ◽

10.2478/awutp-2021-0006 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

M’hammed Benali Benadjemia ◽

Mourad Lounis ◽

Mohamed Miloudi ◽

Nabil Beloufa

Keyword(s):

Metal Oxides ◽

Gas Sensor ◽

Experimental Research ◽

Gas Sensors ◽

Laboratory Tests ◽

Room Temperature ◽

Operating Temperature ◽

Experimental Methodology ◽

Security Measures ◽

Chemical Behavior

Abstract This paper contains experimental research to minimize the basic limits of the SnO2 semiconductor oxide gas sensor. The operating temperature is high. In addition, their selectivity diminishes with gasses having the same chemical behavior. An experimental methodology is presented to overcome the difficulties of these metal oxides. The efficiency of the gas sensors made of Ag continuously doped at room temperature is excellent. At the end of the testing processes and security measures supplied, laboratory tests and experiments will be conducted to guarantee the acceptability of the planned study.

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Preparation and Application of 2D MXene-Based Gas Sensors: A Review

Chemosensors ◽

10.3390/chemosensors9080225 ◽

2021 ◽

Vol 9 (8) ◽

pp. 225

Author(s):

Qingting Li ◽

Yanqiong Li ◽

Wen Zeng

Keyword(s):

Composite Materials ◽

Specific Surface ◽

Surface Area ◽

Gas Sensor ◽

Specific Surface Area ◽

Gas Sensors ◽

Room Temperature ◽

Gas Sensing ◽

Interlayer Spacing ◽

Preparation Methods

Since MXene (a two-dimensional material) was discovered in 2011, it has been favored in all aspects due to its rich surface functional groups, large specific surface area, high conductivity, large porosity, rich organic bonds, and high hydrophilicity. In this paper, the preparation of MXene is introduced first. HF etching was the first etching method for MXene; however, HF is corrosive, resulting in the development of the in situ HF method (fluoride + HCl). Due to the harmful effects of fluorine terminal on the performance of MXene, a fluorine-free preparation method was developed. The increase in interlayer spacing brought about by adding an intercalator can affect MXene’s performance. The usual preparation methods render MXene inevitably agglomerate and the resulting yields are insufficient. Many new preparation methods were researched in order to solve the problems of agglomeration and yield. Secondly, the application of MXene-based materials in gas sensors was discussed. MXene is often regarded as a flexible gas sensor, and the detection of ppb-level acetone at room temperature was observed for the first time. After the formation of composite materials, the increasing interlayer spacing and the specific surface area increased the number of active sites of gas adsorption and the gas sensitivity performance improved. Moreover, this paper discusses the gas-sensing mechanism of MXene. The gas-sensing mechanism of metallic MXene is affected by the expansion of the lamellae and will be doped with H2O and oxygen during the etching process in order to become a p-type semiconductor. A p-n heterojunction and a Schottky barrier forms due to combinations with other semiconductors; thus, the gas sensitivities of composite materials are regulated and controlled by them. Although there are only several reports on the application of MXene materials to gas sensors, MXene and its composite materials are expected to become materials that can effectively detect gases at room temperature, especially for the detection of NH3 and VOC gas. Finally, the challenges and opportunities of MXene as a gas sensor are discussed.

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2D/2D/2D Ti3C2Tx@TiO2@MoS2 Heterostructure as Ultrafast and High-sensitivity NO2 Gas Sensor at Room-temperature

Journal of Materials Chemistry A ◽

10.1039/d1ta09369j ◽

2022 ◽

Author(s):

Zhuo Liu ◽

He Lv ◽

Ying Xie ◽

Jue Wang ◽

Jiahui Fan ◽

...

Keyword(s):

Gas Sensor ◽

Gas Sensors ◽

Room Temperature ◽

Gas Sensing ◽

2D Materials ◽

High Sensitivity ◽

Two Dimensional ◽

No2 Gas Sensor ◽

2D Structure ◽

Sensing Application

The very diverse two-dimensional (2D) materials have bloomed in NO2 gas sensing application that provide new opportunities and challenges in function oriented gas sensors. In this work, a 2D/2D/2D structure...

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

Nanomaterials ◽

10.3390/nano10030462 ◽

2020 ◽

Vol 10 (3) ◽

pp. 462 ◽

Cited By ~ 2

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.

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Micro Sensor Operating at Room Temperature

MRS Proceedings ◽

10.1557/proc-828-a7.1 ◽

2004 ◽

Vol 828 ◽

Cited By ~ 1

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.

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Optimization of SnO2-Based CMOS-Integrated Gas Sensors by Mono-, Bi- and Trimetallic Nanoparticles

Proceedings ◽

10.3390/proceedings2020056043 ◽

2021 ◽

Vol 56 (1) ◽

pp. 43

Author(s):

Robert Wimmer-Teubenbacher ◽

Florentyna Sosada-Ludwikowska ◽

Anton Köck ◽

Stephan Steinhauer ◽

Mukhles Sowwan ◽

...

Keyword(s):

Thin Film ◽

Gas Sensor ◽

Gas Sensors ◽

Sno2 Thin Film ◽

Sensor Devices ◽

Sputter Deposited

In this paper, we report on the optimization of SnO2-based thin film gas sensor devices by mono-, bi- and trimetallic nanoparticles. Ag, AgRu, and AgRuPd nanoparticles are sputter deposited on CMOS-integrated SnO2-thin film gas sensor devices. The CMOS device is a worldwide unique chip containing an array of eight microhotplates. The response towards the target gas CO was dramatically increased from 10% to more than 70% by using trimetallic AgRuPd nanoparticles.

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Room-Temperature ZnO Nanoparticle Ethanol Gas Sensors under UV Illumination

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.486.39 ◽

2012 ◽

Vol 486 ◽

pp. 39-43 ◽

Cited By ~ 1

Author(s):

S.P. Chang

Keyword(s):

Gas Sensor ◽

Gas Sensors ◽

Spin Coating ◽

Room Temperature ◽

Uv Light ◽

Light Illumination ◽

Zno Nanoparticle ◽

Uv Illumination ◽

Potential Applications ◽

Nanoparticle Film

A zinc oxide (ZnO) nanoparticle gas sensor was formed by spin coating. We annealed the film at 400, 600, and 800°C for 1 h in air to create a gas sensor. The responses of the gas sensor to ethanol under UV light illumination were investigated. We found that the ZnO nanoparticle film annealed at 800°C had the highest sensitivity. This can be attributed to the fact that the defects of ZnO nanoparticle film annealed at 800°C are considerably more than those for the film annealed at other temperatures. This study demonstrates that ZnO nanoparticles have potential applications as room-temperature ethanol sensors.

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Properties of gas sensor using CNTs thin film prepared by PLD/CVD method

MRS Proceedings ◽

10.1557/proc-0900-o09-08 ◽

2005 ◽

Vol 900 ◽

Author(s):

Tsuyoshi Ueda ◽

Hideyuki Norimatsu ◽

M.M.H. Bhuiyan ◽

Tomoaki Ikegami ◽

Kenji Ebihara

Keyword(s):

Thin Film ◽

Gas Sensor ◽

Gas Sensors ◽

Room Temperature ◽

Catalyst Particle ◽

High Sensitivity ◽

Laser Pulses ◽

Nano Particles ◽

Film Sensor ◽

Cvd Method

ABSTRACTCarbon nanotube (CNT) is a promising material which has potential for applications to various nanotechnology devices owing to its unique features like high electrical conductivity, mechanical strength and large specific surface area. Recently, gas sensors using CNTs or carbon nano-fiber, which have extremely high sensitivity at a room temperature with fast response, have been reported. Being exposed to oxidizing gas like NO, NO2 or O3, the conductance of the single-walled carbon nanotubes (SWNTs) changes due to charge transfer between the SWNT surface and gas molecules adsorbed. Therefore CNTs will be applicable to O2 and O3 gas sensors in various fields.CNTs thin film sensor was prepared and its performance was investigated. CNTs thin film was prepared on a SiN substrate using PLD/CVD method. To prepare a sensor device an Al2O3 substrate with Pt interdigital electrodes (sensor substrate) was used. In this method, Fe catalytic thin film was deposited by pulsed laser deposition (PLD) method using KrF excimer laser of wavelength 248 nm, repetition rate 10 Hz, energy fluence 3 J/cm2. During PLD process the substrate temperature and the ambient gas pressure were kept at room temperature of 25 °C and 3.5×10−5 Torr, respectively. The thickness and roughness of the films were modified by changing a number of ablation laser pulses from 300 to 3,000. A small number of laser pulses deposited Fe nano-particles of less than 10 nm in diameter on the substrate. We used 1000 pulses for a catalytic Fe film preparation as small-sized catalyst is necessary to grow SWNTs. CNTs were grown from Fe thin film on Si or sensor substrates by thermal CVD method. Ethylene gas was used as carbon source. The substrate was set in the quartz reaction tube heated to 1000 °C in an electric furnace. CNTs were grown for 20 ∼ 40 minutes. In our previous studies, it was found that SWNTs can grow under this process. The prepared CNTs were characterized using SEM, TEM and Raman spectroscopy. From SEM observation, randomly oriented CNTs were found on both the Si substrate and the sensor substrate. A diameter of CNTs was found 20 ∼ 50 nm which tended to be proportional to the size of catalyst particle.The Sensitivity of CNT gas sensor was evaluated by measuring the electrical characteristic of the sensor. The sensor was exposed to NO gas of different concentration in a chamber. Resistance of the sensor was measured by two-terminal method, while the sensor was heated from room temperature to a high temperature on a block heater. The Sensitivity of CNT gas sensors, response time and reproducibility was measured. Initial resistance of the film was about 450 and it decreases with temperature increase. This shows that a prepared CNTs sensor film has semiconductor characteristics. Measured maximum sensitivity of CNTs gas sensor was 6.9 % at sensor temperature 290 deg. Detail studies and the latest data will be presented at the symposium.

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Zinc Phthalocyanine Thin Film-Based Optical Waveguide H2S Gas Sensor

Photonic Sensors ◽

10.1007/s13320-021-0623-8 ◽

2021 ◽

Author(s):

Kediliya Wumaier ◽

Gulgina Mamtmin ◽

Qingrong Ma ◽

Asiya Maimaiti ◽

Patima Nizamidin ◽

...

Keyword(s):

Thin Film ◽

Gas Sensor ◽

Optical Waveguide ◽

Gas Sensors ◽

Room Temperature ◽

Detection System ◽

Cost Effective ◽

Zinc Phthalocyanine ◽

Highly Sensitive ◽

H2s Gas Sensor

AbstractThe detection of hydrogen sulfide (H2S) is essential because of its toxicity and abundance in the environment. Hence, there is an urgent requisite to develop a highly sensitive and economical H2S detection system. Herein, a zinc phthalocyanine (ZnPc) thin film-based K+-exchanged optical waveguide (OWG) gas sensor was developed for H2S detection by using spin coating. The sensor showed excellent H2S sensing performance at room temperature with a wide linear range (0.1 ppm–500 ppm), reproducibility, stability, and a low detection limit of 0.1 ppm. The developed sensor showed a significant prospect in the development of cost-effective and highly sensitive H2S gas sensors.

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