The Preparation of ZnO Gas-Sensing Material by Nucleation-Crystallization Separation Method

2010 ◽  
Vol 152-153 ◽  
pp. 1031-1037
Author(s):  
Xiu Tao Ge ◽  
Jun Hai Wang ◽  
Ding Wang ◽  
Jia Qiang Xu
Keyword(s):  
Gas Sensing ◽  
X Ray Diffraction ◽  
Distribution Method ◽  
Static State ◽  
X Ray ◽  
Sensing Material ◽  
Gas Sensing Properties ◽  
Phase Temperature ◽  
Co Precipitation ◽  
Better Than

The ZnO nanoparticles were synthesized by Nucleation-Crystallization Separation and co-precipitation. The structures and formed phase temperature of the samples were researched by X-ray diffraction (XRD) and DSC -TGA. Gas sensing properties of the samples were measured by a stationary state gas distribution method under static state. The results show that the ZnO prepared from Nucleation-Crystallization Separation has a higher response to 50 ppm ethanol and gasoline than ZnO prepared from co-precipitation. The sensitivity of ZnO prepared from Nucleation-Crystallization Separation to 50 ppm ethanol and gasoline are 34 and 68, which is better than the sensitivity of ZnO prepared from co-precipitation (17 and 28). The good sensing property may be due to the independence of nucleation and crystallization steps, which helps the more uniformity and thermal stability and the larger space utilization of ZnO particles.

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.

scholarly journals Facile Hydrothermal Synthesis and Basic Gas-Sensing Properties of Two Three-Dimensional Nanostructures of SnO2

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Lingna Xu ◽  
Weigen Chen ◽  
Caisheng Wang ◽  
Tuoyu Gao ◽  
Qu Zhou
Keyword(s):  
Gas Sensing ◽  
Three Dimensional ◽  
Hierarchical Architecture ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Sensor Applications ◽  
Sensing Material ◽  
Gas Sensing Properties ◽  
Thin Nanosheets

The hierarchical SnO2sphere-like architecture, consisting of numerous thin nanosheets, was successfully synthesized via a facile hydrothermal method. The structures and morphologies of this hierarchical architecture were characterized in detail by means of powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and Brunauer-Emmett-Teller (BET). Further comparative experiments of gas-sensing performances of the as-prepared SnO2were investigated towards ethanol. It shows this three-dimensional, sheet-spheres, SnO2as a potential gas-sensing material for a broad range of future sensor applications, like sensitive response to other gases such as hydrogen, carbonic oxide, and methane.

Influence of Doping on Structure and H2 Sensitivity of Nano-SnO2

2010 ◽  
Vol 96 ◽  
pp. 105-110 ◽  
Author(s):  
Hai Feng Liu ◽  
Tong Jiang Peng ◽  
Hong Juan Sun ◽  
Liang Fan ◽  
Boa Gang Guo
Keyword(s):  
Gas Sensing ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
X Ray ◽  
Sensing Material ◽  
Crystal Properties ◽  
Co Precipitation ◽  
Special Environment ◽  
Semiconductor Properties

In order to improve the gas sensitivity of SnO2, Ni-doped and Co-doped nano-powders were prepared by the homogenous co-precipitation method using analytical pure SnCl4•5H2O and NH3•H2O as main materials under different doped ratios n (M2+)/n (Sn4+). The gas sensors were made by the thick film technique on mica substrates. The structure and crystal properties of the samples were investigated by X-ray diffraction (XRD). The results indicated that Sn4+ in the crystal lattice of SnO2 was partly replaced by M2+, which resulted in the change of the M-O bond lengths and the lattice parameters. The sensitivities of the sensors in H2 atmosphere with different concentrations at 75°C were tested. As a result, doped M2+ especially Ni2+ improves its H2 sensitivity, the sensitivities increases linearly with the increasing H2 concentration, and the best doping n(M2+)/n(Sn4+) of preparing gas-sensing material were obtained. The results show that doping which leads to the asymmetry of electrovalent balance of M-O octahedrons improves the activities and semiconductor properties of the powders. These studies play an important part in detecting reductive gases in special environment.

Synthesis and Gas Sensing Properties of SnO2-CuO Nanocomposites

2013 ◽  
Vol 645 ◽  
pp. 129-132 ◽  
Author(s):  
Jantasom Khanidtha ◽  
Suttinart Noothongkaew ◽  
Supakorn Pukird
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Precipitation Method ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Co Precipitation

SnO2-CuO nanocomposites have been synthesized with the simple co-precipitation method for gas sensing properties. Sn and CuO powder were the starting materials. The synthesized products were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that SnO2-CuO nanocomposites have a tetragonal and monoclinic structure, respectively. SEM images verify that the some microballs are up to 10 µm and nanorods have a diameter range from 10-100 nm, while length ranges a few micrometers. The nanocomposite products were highly sensitivity to CO2gas at room temperature.

scholarly journals Mg-doped and chemo-thermally treated ZnO nanoflowers for ethanol sensing

2021 ◽  
Author(s):  
Santanu Maity ◽  
P.P Sahu ◽  
Tiju Thomas
Keyword(s):  
Gas Sensing ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Applications ◽  
Wide Range ◽  
Doped Zno ◽  
Ethanol Sensing ◽  
Better Than ◽  
Mg Doped

Abstract ZnO nanostructures are promising for a wide range of applications, including gas sensors. Ethanol sensing using ZnO remains unexplored though. In this paper, we report ethanol-sensing using un-doped ZnO nano flowers and Mg doped ZnO nano flowers. These are grown using a rather simple chemo-thermal process, making this a plausibly scalable technology. To study the structural and morphological properties of undoped ZnO and Mg doped ZnO nanoflowers, Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), x-ray diffraction and Field Emission Scanning Electron Microscopy (FESEM) are carried out. Ethanol sensing properties of undoped ZnO and Mg doped ZnO nanoflower devices are investigated toward different ethanol concentration (concentration range of 1–600 ppm at 100°C–200°C). Our findings show that 15% Mg doped ZnO nano flower is better than ZnO nano flower for ethanol gas-sensing applications.

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.

Method for synthesizing ZnO of different nanostructures by electrospinning and study of their gas sensing properties

2019 ◽  
Vol 33 (25) ◽  
pp. 1950297
Author(s):  
Xiang-Bing Li ◽  
Shu-Yi Ma ◽  
Fu-Rong Li ◽  
Yu-Xiang Zhao ◽  
Xiao-Bin Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Component Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrospinning Method ◽  
Gas Sensing Properties ◽  
Zno Nanofibers ◽  
Scanning Electron

The properties of nanomaterials usually depend on their microstructures, the same material of different microstructures could be used for various applications. However, most devices could only synthesize a single microstructure, so it is meaningful that the different microstructures were synthesized by one method. In our study, electrospinning was applied to fabricate ZnO nanofibers and nanoparticles. In this approach, Zn(Ac)/PVP composite fibers of different component ratio were synthesized by electrospinning method which was subsequently calcined and formed ZnO nanofibers and nanoparticles. The microstructure, chemical composition and gas sensing were investigated with scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and WS-60A gas sensing measurement system. The synthesis mechanisms of ZnO nanofibers and nanoparticles were discussed in detail.

A Metastable Ion (III) Oxide Phase (ε-Fe2O3): Preparation and Gas Sensing Properties

2016 ◽  
Vol 697 ◽  
pp. 737-740 ◽  
Author(s):  
Ming Jing Wang ◽  
Hui Ming Ji ◽  
Ya Lu Chen ◽  
Qian Qian Jia
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Sol Gel ◽  
Oxide Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Addition Amount ◽  
Scanning Electron

ε-Fe2O3 is a rare and metastable iron (III) oxide phase. ε-Fe2O3/SiO2 composites were prepared by combining the reverse-micelle and sol-gel methods. An appropriate amount of Ba2+ was needed in this system to promote the formation of ε-Fe2O3 nanorods in SiO2. The size of nanorods varied with different Ba2+ addition amount and sintering procedure. Then pure ε-Fe2O3 nanorods were obtained after stripping SiO2 by etching due to NaOH aqueous solution. The as-synthesized ε-Fe2O3 nanorods were discussed using X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). Interestingly, metastable ε-Fe2O3 nanorods showed a promising performance for the response for ethanol, compared with the stable phases of α-Fe2O3 and γ-Fe2O3. It indicates that nanostructure ε-Fe2O3 (including ε-Fe2O3 nanorods) could be a valuable material for the fabrication of advanced sensing devices.

Mo-W-O thin films for CO sensing

2000 ◽  
Vol 638 ◽  
Author(s):  
Elisabetta Comini ◽  
Matteo Ferroni ◽  
Vincenzo Guidi ◽  
Giuliano Martinelli ◽  
Michele Sacerdoti ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
Weight Ratio ◽  
X Ray Diffraction ◽  
Composite Target ◽  
X Ray ◽  
Structural Characterisation ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Response And Recovery

AbstractThe Mo-W-O thin films were deposited by RF reactive sputtering from composite target of W and Mo (20:80 weight ratio). Structural characterisation was carried out by X-ray diffraction spectroscopy and the composition of the film was obtained by Rutherford backscattering analysis. The layers were investigated by volt-amperometric technique for electrical and gas-sensing properties. The films were capable of sensing CO. No effect of poisoning of the surface was recorded and recovery of the resistance was complete. A concentration of CO as low as 15 ppm produced a relative variation in the conductance of 390% with response and recovery times of about 2 minutes at a working temperature of 200°C.

Au-sensitized WO3 nanoparticles synthesized and their enhanced acetone sensing properties

2018 ◽  
Vol 11 (04) ◽  
pp. 1850071 ◽  
Author(s):  
Dongping Xue ◽  
Zhanying Zhang
Keyword(s):  
Recovery Time ◽  
Gas Sensing ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Properties ◽  
Response Recovery ◽  
Two Samples ◽  
Gas Sensing Properties ◽  
Scanning Electron

Au-sensitized WO3 nanoparticles have been synthesized by a facile two-step hydrothermal method. The structures, morphologies and surface compositions of the materials were characterized by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM). The test results show that we have prepared higher purity Au-sensitized WO3 nanoparticles. The gas-sensing properties of pure and Au-sensitized WO3 nanoparticles on acetone vapor were further investigated. The results obtained show that the response-recovery time of the two samples prepared is relatively short compared to that reported in the current literature. The Au-sensitized WO3 nanoparticles are significantly more sensitive and selective than the pure WO3 nanoparticles. This may be mainly attributed to the synergy between Au and WO3. It is expected that the Au-sensitized WO3 nanoparticles thus prepared can also be used for research in other fields.

Sign in / Sign up

Export Citation Format

Share Document