Alumina decorated TiO2 nanotubes with ordered mesoporous walls as high sensitivity NOx gas sensors at room temperature

Nanoscale ◽  
2013 ◽  
Vol 5 (18) ◽  
pp. 8569 ◽  
Author(s):  
Renjiang Lü ◽  
Wei Zhou ◽  
Keying Shi ◽  
Ying Yang ◽  
Lei Wang ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Tio2 Nanotubes ◽  
Room Temperature ◽  
High Sensitivity ◽  
Ordered Mesoporous

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

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...

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.

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.

Sonochemical synthesis of Au nanowires in the III–I oxidation state bridged by 4,4′-dicyanamidobiphenyl and their application as selective CO gas sensors

2015 ◽  
Vol 44 (5) ◽  
pp. 2488-2495 ◽  
Author(s):  
Leila Tabrizi ◽  
Hossein Chiniforoshan
Keyword(s):  
Oxidation State ◽  
Gas Sensors ◽  
Room Temperature ◽  
High Sensitivity ◽  
Sonochemical Synthesis ◽  
Au Nanowires ◽  
Co Gas

Au nanowires of bpH2 were synthesized and used for gas sensors with high sensitivity to CO at room temperature.

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

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.

scholarly journals A Review on Functionalized Graphene Sensors for Detection of Ammonia

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1443
Author(s):  
Xiaohui Tang ◽  
Marc Debliquy ◽  
Driss Lahem ◽  
Yiyi Yan ◽  
Jean-Pierre Raskin
Keyword(s):  
Metal Oxides ◽  
Gas Sensors ◽  
Mass Production ◽  
Metallic Nanoparticles ◽  
Room Temperature ◽  
Organic Molecules ◽  
High Sensitivity ◽  
Functionalized Graphene ◽  
Fast Detection ◽  
Sensor Mass

Since the first graphene gas sensor has been reported, functionalized graphene gas sensors have already attracted a lot of research interest due to their potential for high sensitivity, great selectivity, and fast detection of various gases. In this paper, we summarize the recent development and progression of functionalized graphene sensors for ammonia (NH3) detection at room temperature. We review graphene gas sensors functionalized by different materials, including metallic nanoparticles, metal oxides, organic molecules, and conducting polymers. The various sensing mechanism of functionalized graphene gas sensors are explained and compared. Meanwhile, some existing challenges that may hinder the sensor mass production are discussed and several related solutions are proposed. Possible opportunities and perspective applications of the graphene NH3 sensors are also presented.

Fabricating ZnO Nanorods Sensor for Chemical Gas Detection at Room Temperature

2007 ◽  
Vol 7 (12) ◽  
pp. 4439-4442 ◽  
Author(s):  
Chuanwei Cheng ◽  
Guoyue Xu ◽  
Haiqian Zhang ◽  
Yan Luo
Keyword(s):  
Gas Sensors ◽  
Potential Application ◽  
Room Temperature ◽  
Gas Sensing ◽  
Zno Nanorods ◽  
High Sensitivity ◽  
Gas Detection ◽  
Highly Sensitive ◽  
Sensing Characteristics

We present a sensor fabricated by simply casting ZnO nanorods on a microelectrodes array for chemical gas detection at room temperature. The ammonia and ethanol gas sensing characteristics were carefully investigated. The sensor exhibited high sensitivity for both ammonia and ethanol gases. The response and recover time are less than 20 seconds, respectively. Present results demonstrate the potential application of ZnO nanorods for fabricating highly sensitive gas sensors.

Hemin-Functionalized InAs-Based High Sensitivity Room Temperature NO Gas Sensors

2011 ◽  
Vol 116 (1) ◽  
pp. 826-833 ◽  
Author(s):  
Aruna Dedigama ◽  
Michael Angelo ◽  
Pete Torrione ◽  
Tong-Ho Kim ◽  
Scott Wolter ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Room Temperature ◽  
High Sensitivity

scholarly journals Ultrafast Room Temperature Synthesis of Porous Polythiophene via Atmospheric Pressure Plasma Polymerization Technique and Its Application to NO2 Gas Sensors

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1783
Author(s):  
Choon-Sang Park ◽  
Do Yeob Kim ◽  
Eun Young Jung ◽  
Hyo Jun Jang ◽  
Gyu Tae Bae ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Atmospheric Pressure ◽  
Plasma Polymerization ◽  
Room Temperature ◽  
Atmospheric Pressure Plasma ◽  
High Sensitivity ◽  
Plasma Jets ◽  
Temperature Synthesis ◽  
Pressure Plasma ◽  
Sensing Material

New nanostructured conducting porous polythiophene (PTh) films are directly deposited on substrates at room temperature (RT) by novel atmospheric pressure plasma jets (APPJs) polymerization technique. The proposed plasma polymerization synthesis technique can grow the PTh films with a very fast deposition rate of about 7.0 μm·min−1 by improving the sufficient nucleation and fragment of the thiophene monomer. This study also compares pure and iodine (I2)-doped PTh films to demonstrate the effects of I2 doping. To check the feasibility as a sensing material, NO2-sensing properties of the I2-doped PTh films-based gas sensors are also investigated. As a result, the proposed APPJs device can produce the high density, porous and ultra-fast polymer films, and polymers-based gas sensors have high sensitivity to NO2 at RT. Our approach enabled a series of processes from synthesis of sensing materials to fabrication of gas sensors to be carried out simultaneously.

UV-assisted High-sensitivity Room-temperature Pd-gated HEMT NO2Gas Sensor

2021 ◽  
Author(s):  
Chong Xing ◽  
Dongcheng Xie ◽  
Haochen Zhang ◽  
Kang Song ◽  
Lei Yang ◽  
...  
Keyword(s):  
Room Temperature ◽  
High Sensitivity
Sign in / Sign up

Export Citation Format

Share Document