scholarly journals EFFECT OF ANNEALED TEMPERATURE ON NO2 GAS-SENSING PERFORMANCES OF SnO2 NANOWIRE SENSORS

2018 ◽  
Vol 54 (1A) ◽  
pp. 214
Author(s):  
Do Dang Trung
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
X Ray Diffraction ◽  
Research Attention ◽  
No2 Gas Sensor ◽  
Sno2 Nanowires ◽  
Pt Electrodes ◽  
Different Temperatures ◽  
Gas Response ◽  
Sensing Performance

NO2 gas is a highly toxic gas and emitted from vehicles such as motocycles and internal engine transportations. It is one of the major reasons which cause air pollution in recent years, especially in big cities. Therefore, the development of NO2 gas sensor for environmental monitoring has been gained research attention in the global. In this work, we report a simple and effective method to prepare SnO2 nanowire gas sensors. The SnO2 nanowires were directly grown on the unplosihed Al2O3 substrate equipped with a pair of Pt-electrodes. The morphology and microstructure of as-grown nanowires have been investigated via X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and transimission electron microscopy (TEM). The results indicated that the diameters and lengths of nanowires are about 60 – 100 nm and tens of μm, respectively. The gas-sensing performance of the SnO2 nanowires sensors annealed at different temperatures have also investigated. The results revealed that the annealed temperatures of 400 C and 500 oC do not affected on gas-sensing performance of SnO2 nanowires sensors, while the annealed temperature of 600oC results in strong decrease in NO2 gas response as compared with as-grown SnO2 nanowires sensor.

scholarly journals Sputtered SnO2/ZnO Heterostructures for Improved NO2 Gas Sensing Properties

Chemosensors ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 67 ◽  
Author(s):  
Bharat Sharma ◽  
Ashutosh Sharma ◽  
Monika Joshi ◽  
Jae-ha Myung
Keyword(s):  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Operating Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Response Recovery ◽  
No2 Gas Sensor ◽  
Highly Sensitive ◽  
Gas Sensing Properties ◽  
Gas Response

A highly sensitive and selective NO2 gas sensor dependent on SnO2/ZnO heterostructures was fabricated using a sputtering process. The SnO2/ZnO heterostructure thin film samples were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). Sensors fabricated with heterostructures attained higher gas response (S = 66.9) and quicker response-recovery (20 s, 45 s) characteristics at 100 °C operating temperature towards 100 ppm NO2 gas efficiently in comparison to sensors based on their mono-counterparts. The selectivity and stability of SnO2/ZnO heterostructures were studied. The more desirable sensing mechanism of SnO2/ZnO heterostructures towards NO2 was described in detail.

scholarly journals Effect of Growth Temperature and Time on Morphology and Gas Sensitivity of Cu2O/Cu Microstructures

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Ling Wu ◽  
Lun Zhang ◽  
Zhipeng Xun ◽  
Guili Yu ◽  
Liwei Shi
Keyword(s):  
Electron Microscopy ◽  
Gas Sensors ◽  
Gas Sensing ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
X Ray ◽  
Transmission Electron ◽  
Wide Range ◽  
Gas Response

A facile hydrothermal synthesis with CuSO4as the copper source was used to prepare micro/nano-Cu2O. The obtained samples have been characterized by X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). With increasing the reaction temperature and time, the final products were successively Cu2O octahedron microcrystals, Cu2O/Cu composite particles, and a wide range of Cu spherical particles. The gas sensitivity of products towards ethanol and acetone gases was studied. The results showed that sensors prepared with Cu2O/Cu composites synthesized at 65°C for 15 min exhibited optimal gas sensitivity. The gas sensing mechanism and the effect of Cu in the enhanced gas response were also elaborated. The excellent gas sensitivity indicates that Cu2O/Cu composites have potential application as gas sensors.

scholarly journals Enhanced gas-sensing performance of Au-modified ZnO nanoparticles synthesized using bamboo cellulose as a template

2016 ◽  
Vol 34 (4) ◽  
pp. 708-714 ◽  
Author(s):  
Yan Li ◽  
Fang-Xian Zhao ◽  
Xiao-Xue Lian
Keyword(s):  
Electron Microscopy ◽  
Zno Nanoparticles ◽  
Gas Sensing ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
Calcination Process ◽  
Transmission Electron ◽  
Modified Zno Nanoparticles ◽  
Sensing Performance

AbstractAu-modified ZnO (Au/ZnO) nanoparticles (NPs) synthesized using bamboo cellulose template and calcination process were characterized using X-ray diffraction, field-emission scanning electron microscopy, and transmission electron microscopy. The gas-sensing performance of Au/ZnO NPs based sensors was also examined. The results indicated that the Au/ZnO NPs exhibited enhanced gas-sensing performance compared with that of pure ZnO. The response of the Au/ZnO NPs to 100 ppm ethanol (50) at 240 °C was nearly 2.7 times higher than that to acetone (18.4) and approximately 12.5 times higher than that to benzene (4.1), carbon monoxide (1.6), hydrogen (1.6), and methane (1.8), respectively, which demonstrated their higher selectivity to ethanol versus other gases. This high response to ethanol could be attributed to the small size, Schottky barrier, and catalysis.

scholarly journals Synthesis, Characterization, and Hydrogen Gas Sensing of ZnO/g-C3N4 Nanocomposite

2021 ◽  
Vol 10 (1) ◽  
pp. 3
Author(s):  
Arif Ibrahim ◽  
Uzma Bano Memon ◽  
Siddartha Prakash Duttagupta ◽  
Raman R. K. Singh ◽  
Arindam Sarkar
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Hydrogen Gas ◽  
X Ray Diffraction ◽  
Material Synthesis ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Recovery Times ◽  
Response And Recovery ◽  
Gas Response

In this paper, the preparation of the ZnO/g-C3N4 nanocomposite is discussed. The synthesis of nanocomposite is performed by the direct pyrolysis of the precursor (zinc acetate hexahydrate). The material synthesis is validated by different characterization tools, such as X-ray Diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM). The SEM and TEM analysis revealed the formation of nanorods on g-C3N4 support. The gas sensing property of the ZnO/g-C3N4 was studied for various concentrations of hydrogen gas. Response and recovery times were recorded by the sensor.

scholarly journals Influence of Metal Catalyst on SnO2 Nanowires Growth and Gas Sensing Performance

Proceedings ◽  
2017 ◽  
Vol 1 (4) ◽  
pp. 460 ◽  
Author(s):  
Dario Zappa ◽  
Rebecca Melloni ◽  
Valentin-Adrian Maraloiu ◽  
Nicola Poli ◽  
Marco Rizzoni ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Metal Catalyst ◽  
Sno2 Nanowires ◽  
Nanowires Growth ◽  
Sensing Performance

Microstructure and Properties of Nanosemicrystalline Si3N4 Ceramics with Doped Sintering Additives: Part II. Phase Transformation and Microstructural Control

1998 ◽  
Vol 13 (9) ◽  
pp. 2588-2596 ◽  
Author(s):  
K. H. Ryu ◽  
J-M. Yang
Keyword(s):  
Electron Microscopy ◽  
Pressureless Sintering ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sintering Additives ◽  
Different Temperatures ◽  
Si3n4 Ceramics ◽  
Scanning Electron ◽  
Microstructural Control

The low temperature pressureless sintering of a nanosized Si3N4 powder with doped sintering additives was investigated. The microstructural evolution during sintering at different temperatures was analyzed using x-ray diffraction and scanning electron microscopy. The effect of using nanosized Si3N4 powder as a catalyst to accelerate the α→β–Si3N4 transformation of a commercial Si3N4 powder with larger particle sizes was also investigated. Finally, two stage sintering was used to study the feasibility of controlling the microstructure and the mechanical properties of the nanosized silicon nitride.

A Novel Tungsten Trioxide Based Gas Sensor for Indoor Formaldehyde Detection

2021 ◽  
Vol 16 (3) ◽  
pp. 363-367
Author(s):  
Gaoqi Zhang ◽  
Fan Zhang ◽  
Kaifang Wang ◽  
Tao Tian ◽  
Shanyu Liu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Gas Sensor ◽  
Indoor Air ◽  
Gas Sensing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Material ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Gas Response

Accurate and real-time detection of formaldehyde (HCHO) in indoor air is urgently needed for human health. In this work, a ceramic material (WO3·H2O) with unique structure was successfully prepared using an efficient hydrothermal method. The crystallinity, morphology and microstructure of the as-prepared sensing material were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) as well as transmission electron microscope (TEM). The characterization results suggest that the as-prepared sample is composed of square-like nanoplates with uneven surface. Formaldehyde vapor is utilized as the target gas to investigate gas sensing properties of the synthesized novel nanoplates. The testing results indicate that the as-fabricated gas sensor exhibit high gas response and excellent repeatability to HCHO gas. The response value (Ra/Rg) is 24.5 towards 70 ppm HCHO gas at 350 °C. Besides, the gas sensing mechanism was described.

Effective decoration of Pd nanoparticles on the surface of SnO2 nanowires for enhancement of CO gas-sensing performance

2014 ◽  
Vol 265 ◽  
pp. 124-132 ◽  
Author(s):  
Do Dang Trung ◽  
Nguyen Duc Hoa ◽  
Pham Van Tong ◽  
Nguyen Van Duy ◽  
T.D. Dao ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Pd Nanoparticles ◽  
Sno2 Nanowires ◽  
Sensing Performance ◽  
Co Gas

Preparation and Property of Al87Ce3Ni8.5Mn1.5 Nanophase Amorphous Composites

2011 ◽  
Vol 412 ◽  
pp. 263-266
Author(s):  
Hong Wei Zhang ◽  
Li Li Zhang ◽  
Feng Rui Zhai ◽  
Jia Jin Tian ◽  
Can Bang Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Phase ◽  
Volume Fraction ◽  
Material Structure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Different Temperatures

The higher mechanical strength of Al87Ce3Ni8.5Mn1.5 nanophase amorphous composites has been obtained with two methods. The first nanophase amorphous composites are directly produced by the single roller spin quenching technology. The method taken for the second nanophase amorphous composites is at first to obtain amorphous single-phase alloy, followed by annealed at different temperatures .The formative condition, the microstructure, the particle size, the volume fraction of α-Al phase and microhardness of nanophase amorphous composites etc have been investigated and compared by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The microstructure of composites produced by the second method is higher than the former, the fabricated material structure of the system is more uniform and the process is easier to control.

scholarly journals Synthesis of SnO2 nanowires forCO, CH4 and CH3OH gases sensing

2018 ◽  
Vol 14 (8) ◽  
pp. 155014771879075 ◽  
Author(s):  
Khurram Shehzad ◽  
Nazar Abbas Shah ◽  
Muhammad Amin ◽  
Murrawat Abbas ◽  
Waqar Adil Syed
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gas Sensing ◽  
Reduction Process ◽  
X Ray ◽  
Sensing Applications ◽  
Microscopy Investigation ◽  
Sno2 Nanowires ◽  
Visible Spectra ◽  
Scanning Electron

Synthesis of one-dimensional nanostructures, such as nanowires, is of vigorous significance for achieving the desired properties and fabricating functional devices. In this work, we report the synthesis of tin oxide (SnO2) nanowires on gold-catalyzed silicon substrate by carbothermal reduction process. SnO2 nanowires were synthesized with SnO2 and graphite powders as the source materials at atmospheric pressure and temperature of 900°C in the ambience of nitrogen (N2) gas. First, the effect of source material ratio SnO2:C on growth of SnO2 nanowires was studied. The structural, morphological and compositional properties of the samples were investigated by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. The scanning electron microscopy investigation reveals that uniform dense nanowires of SnO2 (diameter ~127 nm and length ~40 µm) were synthesized with vapour–liquid–solid mechanism. Ultraviolet–visible spectra estimate that the optical band gap of the synthesized SnO2 nanowires was 3.72 eV. Second, the gas sensing performance of synthesized SnO2 nanowires was investigated by testing with carbon monoxide (CO), Methane (CH4) and methanol (CH3OH) gases at different operating temperatures and concentrations. Results indicate that the synthesized SnO2 nanowires are highly promising for gas sensing applications.

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