Gas Sensing Characteristics of ZnO-doped SnO2 Sensors for Simulants of the Chemical Agents

2005 ◽  
Vol 486-487 ◽  
pp. 9-12 ◽  
Author(s):  
Kwang-Hyun Yun ◽  
Ky-Youl Yun ◽  
Geon-Young Cha ◽  
Bong Ho Lee ◽  
Jae Chang Kim ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Zinc Acetate Dihydrate ◽  
Chemical Agent ◽  
X Ray Diffraction ◽  
Tin Chloride ◽  
Chemical Agents ◽  
Phase Development ◽  
Semiconductor Gas Sensors ◽  
Sensing Characteristics ◽  
Glycol Methyl Ether

After the 9∙11 terrorism and America-Iraq war, apprehension of mass destruction weapons such as bio-chemical agents calls for much more sensitive sensors which can detect toxic gases. In this study, semiconductor gas sensors based on tin oxide were examined to detect chemical agent simulants: dimethyl-methyl-phosponate (DMMP), di(propylene glycol) methyl ether (DPGME), acetonitrile, and dichloromethane. DMMP((CH3O)3), DPGME(C7H16O3), acetonitrile(CH3CN), and dichloromethane(CH2Cl2) gases are the simulants of nerve agent-sarin, vesicant agent-HN(N(CH2CH2Cl)3), blood agent-AC(HCN), and choking agent-CG(COCl2) gases, repectively. The SnO2 powder was prepared by a coprecipitation method from the mixture of tin chloride and zinc acetate dihydrate. Zinc oxide was doped into SnO2 from 1 wt% to 4 wt% to improve its reliability and sensitivity. To fabricate a thick film, powders were made into paste with organic binder of ethyl cellulose and screen-printed on the alumina substrate. The phase development and morphology of ZnO-doped SnO2 film were investigated by XRD (X-ray diffraction analysis), BET (surface and pore size analyzer), and SEM (scanning electron microscope). The gas sensing characteristics for target gases were examined with a flow-type measurement system. The concentrations of simulants were controlled from 500 ppb to 1500 ppb, and working temperatures were regulated from 250 to 400 .

A Formaldehyde Gas Sensor Based on Zinc Doped Lanthanum Ferrite

2013 ◽  
Vol 873 ◽  
pp. 304-310 ◽  
Author(s):  
Jin Zhang ◽  
Yu Min Zhang ◽  
Chang Yi Hu ◽  
Zhong Qi Zhu ◽  
Qing Ju Liu
Keyword(s):  
Gas Sensing ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Lanthanum Ferrite ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Response And Recovery ◽  
Sensing Characteristics

The gas-sensing properties of zinc doped lanthanum ferrite (Zn-LaFeO3) compounds for formaldehyde were investigated in this paper. Zn-LaFeO3 powders were prepared using sol-gel method combined with microwave chemical synthesis. The powders were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The formaldehyde gas-sensing characteristics for the sample were examined. The experimental results indicate that the sensor based on the sample Zn-LaFeO3 shows excellent gas-sensing properties to formaldehyde gas. At the optimal operating temperature of 250°C, the sensitivity of the sensor based on LaFe0.7Zn0.3O3 to 100ppm formaldehyde is 38, while to other test gases, the sensitivity is all lower than 20. The response and recovery times for the sample to formaldehyde gas are 100s and 100s, respectively.

scholarly journals Liquid petroleum gas sensing performance enhanced by CuO modification of nanocrystalline ZnO-TiO2

2016 ◽  
Vol 34 (3) ◽  
pp. 571-581
Author(s):  
R.B. Pedhekar ◽  
F.C. Raghuwanshi ◽  
V.D. Kapse
Keyword(s):  
Thick Film ◽  
Gas Sensing ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Transmission Electron ◽  
Liquid Petroleum Gas ◽  
Synthesized Materials ◽  
Sensing Characteristics

AbstractNanocrystalline ZnO-TiO2 (with molar ratios 9:1, 7:3, 1:1, 3:7 and 1:9) were successfully synthesized by hydrothermal method. Synthesized materials were examined with the help of X-ray diffraction and transmission electron microscope. Liquid petroleum gas sensing characteristics of the ZnO-TiO2 films were investigated at different operating temperatures. The ZnO-TiO2 thick film (with 1:1 molar ratio) exhibited good response toward liquid petroleum gas as compared to other investigated compositions. Further, liquid petroleum gas sensing characteristics of CuO modified ZnO-TiO2 thick films were investigated. 0.2 M CuO modified ZnO-TiO2 thick film exhibited excellent liquid petroleum gas sensing characteristics such as higher response (~ 1637.49 at 185 °C) with quick response time (~30 s), low recovery time (~70 s), excellent repeatability and stability at low operating temperature.

Pure and Pr-doped Ce4W9O33 with superior hydroxyl scavenging ability: Humidity-independent oxide chemiresistors

2021 ◽  
Author(s):  
Jun-Sik Kim ◽  
Ki Beom Kim ◽  
Huayao Li ◽  
Chan Woong Na ◽  
Kyeorei Lim ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Oxide Semiconductor ◽  
Semiconductor Gas Sensors ◽  
First Time ◽  
Sensing Characteristics ◽  
Standing Problem

Water poisoning has been a long-standing problem in oxide semiconductor gas sensors. Herein, for the first time, we report that pure and Pr-doped Ce4W9O33 provide humidity-independent gas sensing characteristics. The...

scholarly journals Effects of Niobium-Loading on Sulfur Dioxide Gas-Sensing Characteristics of Hydrothermally Prepared Tungsten Oxide Thick Film

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Viruntachar Kruefu ◽  
Anurat Wisitsoraat ◽  
Sukon Phanichphant
Keyword(s):  
Spin Coating ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Sensor Response ◽  
X Ray Diffraction ◽  
Optimal Operating ◽  
Impregnation Process ◽  
X Ray ◽  
Transmission Electron ◽  
Sensing Characteristics

Nb-loaded hexagonal WO3nanorods with 0–1.0 wt% loading levels were successfully synthesized by a simple hydrothermal and impregnation process and characterized for SO2sensing. Nb-loaded WO3sensing films were produced by spin coating on alumina substrate with interdigitated gold electrodes and annealed at 450°C for 3 h in air. Structural characterization by X-ray diffraction, high-resolution transmission electron microscopy, and Brunauer-Emmett-Teller analysis showed that spherical, oval, and rod-like Nb nanoparticles with 5–15 nm mean diameter were uniformly dispersed on hexagonal WO3nanorods with 50–250 nm diameter and 100 nm–5 µm length. It was found that the optimal Nb loading level of 0.5 wt% provides substantial enhancement of SO2response but the response became deteriorated at lower and higher loading levels. The 0.50 wt% Nb-loaded WO3nanorod sensing film exhibits the best SO2sensing performances with a high sensor response of ~10 and a short response time of ~6 seconds to 500 ppm of SO2at a relatively low optimal operating temperature of 250°C. Therefore, Nb loading is an effective mean to improve the SO2gas-sensing performances of hydrothermally prepared WO3nanorods.

Gas Sensing Characteristics of ZnO-doped SnO2 Sensors for Simulants of the Chemical Agents

2005 ◽  
pp. 9-12
Author(s):  
Kwang-Hyun Yun ◽  
Ky-Youl Yun ◽  
Geon-Young Cha ◽  
Bong Ho Lee ◽  
Jae Chang Kim ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Chemical Agents ◽  
Sensing Characteristics

scholarly journals Comparative NO2 Sensing Characteristics of SnO2:WO3 Thin Film Against Bulk and Investigation of Optical Properties of the Thin Film

2018 ◽  
Vol 15 (2) ◽  
pp. 227-233 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Gas Sensing ◽  
Comparative Investigation ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Thin Film Sensors ◽  
Gas Sensing Properties ◽  
Evaporation Technique ◽  
Sensing Characteristics

A comparative investigation of gas sensing properties of SnO2 doped with WO3 based on thin film and bulk forms was achieved. Thin films were deposited by thermal evaporation technique on glass substrates. Bulk sensors in the shape of pellets were prepared by pressing SnO2:WO3 powder. The polycrystalline nature of the obtained films with tetragonal structure was confirmed by X-ray diffraction. The calculated crystalline size was 52.43 nm. Thickness of the prepared films was found 134 nm. The optical characteristics of the thin films were studied by using UV-VIS Spectrophotometer in the wavelength range 200 nm to 1100 nm, the energy band gap, extinction coefficient and refractive index of the thin film were 2.5 eV , 0.024 and 2.51, respectively. Hall measurements confirmed that the films are n-type. The NO2 sensing characteristics of the SnO2:WO3 sensors were studied with various temperatures and NO2 gas concentrations. Both thin film and bulk sensors showed maximum sensitivity at temperature of 250 oC. Thin film sensors showed enhanced response in comparison to that of pellets.

NO-sensing characteristics of ZnO nanorods prepared by the ultrasound radiation method

2007 ◽  
Vol 221 (2) ◽  
pp. 67-72
Author(s):  
J-W Kim ◽  
S-M Park ◽  
E-G Oh ◽  
J-B Yu ◽  
H-G Byun ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Zno Nanorods ◽  
Zinc Nitrate ◽  
X Ray Diffraction ◽  
Radiation Method ◽  
Gas Sensing Properties ◽  
Ultrasound Radiation ◽  
Ceramic Microstructure ◽  
Sensing Characteristics ◽  
Direct Immersion

In this study, zinc oxide (ZnO) sensors were fabricated from ZnO nanorods prepared by ultrasound radiation method, and their gas-sensing properties were investigated for nitric oxide (NO), trimethylamine ((CH3)3N), hydrogen sulphide (H2S), carbon monoxide (CO), and methyl mercaptan (CH3SH). In the procedure, zinc nitrate hydrate (Zn(NO3)2·6H2O) and hexamethyleneteramine (C6H12N4,) were dissolved in deionized water and then the solution was irradiated with high-intensity ultrasound radiation for 1 h by employing a direct immersion of titanium horn. The length of the ZnO nanorods was from 250 nm to 500 nm and the diameter was from 40 nm to 80 nm. The size of the ZnO nanorods can be controlled by the concentration of the solution. The sensing characteristics of these nanostructures were investigated for three kinds of sensor fabricated by different concentrations (0.01, 0.005, and 0.001 M) of solution. It was observed that the property of the sensors was influenced by the morphology. The crystal structure and ceramic microstructure of the ZnO nanorods were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).

scholarly journals Inhomogeneous Oxygen Vacancy Distribution in Semiconductor Gas Sensors: Formation, Migration and Determination on Gas Sensing Characteristics

Sensors ◽  
2017 ◽  
Vol 17 (8) ◽  
pp. 1852 ◽  
Author(s):  
Jianqiao Liu ◽  
Yinglin Gao ◽  
Xu Wu ◽  
Guohua Jin ◽  
Zhaoxia Zhai ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Gas Sensors ◽  
Gas Sensing ◽  
Vacancy Distribution ◽  
Semiconductor Gas Sensors ◽  
Sensing Characteristics

Acetylene Sensing Characteristics of SnO2 Nanowires

2015 ◽  
Vol 1119 ◽  
pp. 132-136
Author(s):  
Bing Wang
Keyword(s):  
Electron Microscopy ◽  
Thermal Evaporation ◽  
Gas Adsorption ◽  
Gas Sensing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Material ◽  
Transmission Electron ◽  
Mems Technology ◽  
Sensing Characteristics

SnO2 nanowires have been fabricated using thermal evaporation of the mixed powders of SnO2 and active carbon with Au catalysts. The morphology and structure of the prepared nanowires are determined on the basis of field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectrometer (EDS), x-ray diffraction (XRD) and transmission electron microscopy (TEM). The comb-shape interdigitating electrode made by MEMS technology is used to auxiliary investigating the gas sensing performance of the synthesized SnO2 nanowires. The SnO2 nanowires have sensing response to acetylene concentration of 1000 ppm under operated temperature of 300°C. The gas sensing mechanism is attributed to the gas adsorption and desorption processes occurring on the surface of the gas sensing material.

scholarly journals Improvement in NO2 Gas Sensing Properties of Semiconductor-Type Sensors by Loading Pt into BiVO4 Nanocomposites at Room Temperature

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5913
Author(s):  
Wang-De Lin ◽  
Shu-Yun Lin ◽  
Murthy Chavali
Keyword(s):  
Recovery Time ◽  
Gas Sensing ◽  
Fast Response ◽  
X Ray Diffraction ◽  
X Ray ◽  
Response Recovery ◽  
Transmission Electron ◽  
Surface Morphologies ◽  
Sensing Characteristics ◽  
Semiconductor Type

In the present study, we report the first attempt to prepare a conducive environment for Pt/BiVO4 nanocomposite material reusability for the promotion of sustainable development. Here, the Pt/BiVO4 nanocomposite was prepared using a hydrothermal method with various weight percentages of platinum for use in NO2 gas sensors. The surface morphologies and structure of the Pt/BiVO4 nanocomposite were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The results showed that Pt added to BiVO4 with 3 wt.% Pt/BiVO4 was best at a concentration of 100 ppm NO2, with a response at 167.7, and a response/recovery time of 12/35 s, respectively. The Pt/BiVO4 nanocomposite-based gas sensor exhibits promising nitrogen dioxide gas-sensing characteristics, such as fast response, highly selective detection, and extremely short response/recovery time. Additionally, the mechanisms of gas sensing in Pt/BiVO4 nanocomposites were explored in this paper.

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