Enhancement of SO2 Gas Sensing Performance of Co3O4 Spinel by Cu Substitution

2020 ◽  
Vol 18 (2) ◽  
pp. 83-88
Author(s):  
P. N. Anantharamaiah ◽  
Sweta Giri
Keyword(s):  
Cobalt Oxide ◽  
Gas Sensor ◽  
Gas Sensing ◽  
Response Times ◽  
Poor Response ◽  
Potential Candidate ◽  
Potential Applicability ◽  
Co Precipitation ◽  
Gas Response ◽  
Sensing Characteristics

Single-phase spinel cobalt oxide (Co3O4) and copper-substituted cobalt oxide (Co2.8Cu0.2O4) nanomaterials were synthesized via a co-precipitation route. To explore the potential applicability of the Co3O4 and Co2.8Cu0.2O4 materials for gas sensor fabrication, their SO2 gas sensing characteristics were studied at three different temperatures using the gas concentration of 3 ppm. Unsubstituted Co3O4 sample exhibits poor response towards SO2 gas whereas the Cu-substituted sample showed superior gas sensing characteristics such as gas response, response time and recovery time at all three temperatures. Among the three studied temperatures, the maximum gas response of 7.5% was found at 200 °C with recovery and response times of 26 sec, indicating an optimal temperature. Our results demonstrate that the nanostructured Co2.8Cu0.2O4 material could be a potential candidate to design SO2 gas sensor for detection of low concentration gas.

scholarly journals Toxic Gas Response for Nanostructured Cobalt Oxide Thin Films

2021 ◽  
Vol 19 (50) ◽  
pp. 20-30
Author(s):  
Suhad A. Hamdan ◽  
Iftikhar M. Ali ◽  
Isam M.Ibrahim
Keyword(s):  
Thin Films ◽  
Cobalt Oxide ◽  
Gas Sensing ◽  
Response Times ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Sensing Properties ◽  
Reducing Gas ◽  
Gas Sensing Properties ◽  
Gas Response

 The gas sensing properties of undoped Co3O4 and doped with Y2O3 nanostructures were investigated. The films were synthesized using the hydrothermal method on a seeded layer. The XRD, SEM analysis and gas sensing properties were investigated for the prepared thin films. XRD analysis showed that all films were polycrystalline, of a cubic structure with crystallite size of (12.6) nm for cobalt oxide and (12.3) nm for the Co3O4:6% Y2O3. The SEM analysis of thin films indicated that all films undoped Co3O4 and doped possessed a nanosphere-like structure. The sensitivity, response time and recovery time to H2S reducing and NO2 oxidizing gases were tested at different operating temperatures. The resistance changed with exposure to the test gas. The results revealed that the Co3O4:6%Y2O3 possessed the highest sensitivity around 90% (at room temperature) and 62.5% (at 150 oC) when exposed to the reducing gas H2S and oxidizing gas NO2, respectively with 0.8sec for both recovery and response times.

Star-Fruit-Shaped CuO Structures for High Performance Ethanol Gas Sensor Device

2021 ◽  
Vol 13 (4) ◽  
pp. 724-733
Author(s):  
Ahmad Umar ◽  
Ahmed A. Ibrahim ◽  
Rajesh Kumar ◽  
Hassan Algadi ◽  
Hasan Albargi ◽  
...  
Keyword(s):  
Gas Sensor ◽  
High Performance ◽  
Crystal Size ◽  
Gas Sensing ◽  
Sensor Applications ◽  
Sensor Device ◽  
Star Fruit ◽  
Micro Structures ◽  
Gas Response ◽  
Structural Crystal

In this paper, star-fruit-shaped CuO microstructures were hydrothermally synthesized and subsequently characterized through different techniques to understand morphological, compositional, structural, crystal, optical and vibrational properties. The formation of star-fruit-shaped structures along with some polygonal and spherical nanostructures was confirmed by FESEM analysis. XRD data and Raman spectrum confirmed the monoclinic tenorite crystalline phase of the CuO with crystal size 17.61 nm. Star-fruit-shaped CuO microstructures were examined for ethanol gas sensing behavior at various operating temperatures and concentrations. The gas response of 135% was observed at the optimal temperature of 225 °C. Due to excellent selectivity, stability and re-usability, the as-fabricated sensor based on star-fruit-shaped CuO micro-structures may be explored for future toxic gas sensor applications.

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.

Gas sensing characteristics of the FET-type gas sensor having inkjet-printed WS2 sensing layer

2019 ◽  
Vol 153 ◽  
pp. 27-32 ◽  
Author(s):  
Yujeong Jeong ◽  
Jongmin Shin ◽  
Yoonki Hong ◽  
Meile Wu ◽  
Seongbin Hong ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Gas Sensing ◽  
Sensing Characteristics

Rh-catalyzed WO3 with anomalous humidity dependence of gas sensing characteristics

RSC Advances ◽  
2014 ◽  
Vol 4 (95) ◽  
pp. 53130-53136 ◽  
Author(s):  
Kwon-Il Choi ◽  
Su-Jin Hwang ◽  
Zhengfei Dai ◽  
Yun Chan Kang ◽  
Jong-Heun Lee
Keyword(s):  
Gas Sensing ◽  
Humidity Dependence ◽  
Gas Response ◽  
Sensing Characteristics

An anomalous humidity dependence of gas sensing characteristics is found for a Rh-loaded WO3 sensor, where the resistance and gas response increased in humid atmospheres.

Fabrication of a propanol gas sensor using p-type nickel oxide nanostructures: The effect of ramping rate towards luminescence and gas sensing characteristics

2020 ◽  
Vol 253 ◽  
pp. 123316 ◽  
Author(s):  
Teboho P. Mokoena ◽  
Kenneth T. Hillie ◽  
Hendrik C. Swart ◽  
Nompumelelo Leshabane ◽  
James Tshilongo ◽  
...  
Keyword(s):  
Nickel Oxide ◽  
Gas Sensor ◽  
Gas Sensing ◽  
Oxide Nanostructures ◽  
P Type ◽  
Sensing Characteristics ◽  
Type Nickel

Hierarchical Flower-Like Microspheres: An Application of Hydrogen Sulfide Gas Sensor for Tunnel Construction

2021 ◽  
Vol 16 (1) ◽  
pp. 1-5
Author(s):  
Chuansheng Wu ◽  
Yuyue Li ◽  
Lingling Qi ◽  
Lingjiang Zhang ◽  
Hao Xu
Keyword(s):  
Gas Sensor ◽  
Gas Sensing ◽  
Fast Response ◽  
Tunnel Construction ◽  
Hydrothermal Route ◽  
Sensing Properties ◽  
Response Recovery ◽  
Gas Sensing Properties ◽  
Gas Response ◽  
Scanning Electron

Hierarchical flower-like WO3 · H2O microspheres assembled by nanosheets were successfully prepared through a simple hydrothermal route. Field emission scanning electron microscopy results indicate that the flower-like WO3 · H2O microspheres are composed of numerous nanosheets, which are interconnected with each other in the sphere shape. In addition, the gas sensing properties of the hierarchical WO3 · H2O microspheres were investigated. It is found that the gas sensor based on the hierarchical WO3 · H2O architectures exhibits excellent gas sensing properties towards H2S gas, including high gas response and fast response/recovery speed.

A Formaldehyde Indoor Gas Sensor Based on Hierarchical α-Molybdenum Trioxide

2021 ◽  
Vol 16 (6) ◽  
pp. 987-992
Author(s):  
Yujun Zhu ◽  
Fan Zhang ◽  
Kaifang Wang ◽  
Yawen Zhang ◽  
Xiuzhi Gu ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Indoor Air ◽  
Gas Sensing ◽  
Molybdenum Trioxide ◽  
Three Dimensional ◽  
Test Results ◽  
Hierarchical Microstructure ◽  
Formaldehyde Sensing ◽  
2D Nanosheets ◽  
Sensing Characteristics

The detection of indoor formaldehyde gas is important because of its highly toxic nature. Herein, the two-dimensional α-MoO3 nanosheets and three-dimensional α-MoO3 hierarchical flowers have been prepared by simple hydrothermal strategy and used as the formaldehyde sensing materials. Their microstructures, morphologies and gas sensing characteristics towards formaldehyde were studied. The test results exhibited that, at the optimal temperature of 250 °C, the sensor performances were enhanced due to the assembly of 2D nanosheets into 3D hierarchical structure. The improved properties were contributed to the formation of the hierarchical microstructure constructed by nanosheets. The hierarchical microstructure based gas sensor has significant potential in indoor air sensing application.

Gold-Doped Oxide Nanocomposites Prepared by Two Solution Methods and Their Gas-Sensing Response

2012 ◽  
Vol 1449 ◽  
Author(s):  
Chien-Tsung Wang ◽  
Huan-Yu Chen ◽  
Yu-Chung Chen
Keyword(s):  
Gas Sensor ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Synthesis Method ◽  
Redox Activity ◽  
Precipitation Method ◽  
X Ray ◽  
Oxide Support ◽  
Solution Methods ◽  
Co Precipitation

ABSTRACTGold species on an oxide support possess variable electronic structures via charge transition so as to increase their chemical redox activity. They are also viably promising for use to enhance gas-sensing response when being exploited in a solid state gas sensor. The synthesis method of the gold-loaded materials plays a crucial role in the functionality. In this paper, we report two types of gold/tin oxide based nanopowders prepared by co-precipitation method and by deposition-precipitation method, respectively. They were evaluated as sensing elements in a semiconductor carbon monoxide (CO) gas sensor. Effects of the material type and CO concentration on sensor response were investigated. Their structural characterizations were done by X-ray photoelectron spectroscopy, X-ray diffraction and transmission electron microscopy. Results demonstrate the surface gold species effective to facilitate CO oxidation in gas atmosphere and promote low-temperature sensor performance.

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