scholarly journals Enhancement of Hydrothermally Co3O4 Thin Films as H2S Gas Sensor by Loading Yttrium Element

2019 ◽  
Vol 16 (1) ◽  
pp. 0221
Author(s):  
Hamdan Et al.

The gas sensing properties of Co3O4 and Co3O4:Y nano structures 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 Co3O4 and Co3O4:Y thin films. XRD analysis shows that all films are polycrystalline in nature, having a cubic structure, and the crystallite size is (11.7)nm for cobalt oxide and (9.3)nm for the Co3O4:10%Y. The SEM analysis of thin films obviously indicates that Co3O4 possesses a nanosphere-like structure and a flower-like structure for Co3O4:Y. The sensitivity, response time and recovery time to a H2S reducing gas were tested at different operating temperatures. The resistance changes with exposure to the test gas. The results reveal that the Co3O4:10%Y possesses the highest sensitivity around 80% at a 100oC operating temperature when exposed to the reducing gas H2S with 0.8sec for both recovery and response times.

2019 ◽  
Vol 16 (1(Suppl.)) ◽  
pp. 0221
Author(s):  
Hamdan Et al.

The gas sensing properties of Co3O4 and Co3O4:Y nano structures 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 Co3O4 and Co3O4:Y thin films. XRD analysis shows that all films are polycrystalline in nature, having a cubic structure, and the crystallite size is (11.7)nm for cobalt oxide and (9.3)nm for the Co3O4:10%Y. The SEM analysis of thin films obviously indicates that Co3O4 possesses a nanosphere-like structure and a flower-like structure for Co3O4:Y. The sensitivity, response time and recovery time to a H2S reducing gas were tested at different operating temperatures. The resistance changes with exposure to the test gas. The results reveal that the Co3O4:10%Y possesses the highest sensitivity around 80% at a 100oC operating temperature when exposed to the reducing gas H2S with 0.8sec for both recovery and response times.


2021 ◽  
Vol 19 (50) ◽  
pp. 20-30
Author(s):  
Suhad A. Hamdan ◽  
Iftikhar M. Ali ◽  
Isam M.Ibrahim

 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.


2021 ◽  
Vol 127 (4) ◽  
Author(s):  
Irmak Karaduman Er ◽  
Memet Ali Yıldırım ◽  
H. Hasan Örkçü ◽  
Aytunç Ateş ◽  
Selim Acar

2015 ◽  
Vol 14 (04) ◽  
pp. 1550011 ◽  
Author(s):  
A. Sharma ◽  
M. Tomar ◽  
V. Gupta ◽  
A. Badola ◽  
N. Goswami

In this paper gas sensing properties of 0.5–3% polyaniline (PAni) doped SnO 2 thin films sensors prepared by chemical route have been studied towards the trace level detection of NO 2 gas. The structural, optical and surface morphological properties of the PAni doped SnO 2 thin films were investigated by performing X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Raman spectroscopy measurements. A good correlation has been identified between the microstructural and gas sensing properties of these prepared sensors. Out of these films, 1% PAni doped SnO 2 sensor showed high sensitivity towards NO 2 gas along with a sensitivity of 3.01 × 102 at 40°C for 10 ppm of gas. On exposure to NO 2 gas, resistance of all sensors increased to a large extent, even greater than three orders of magnitude. These changes in resistance upon removal of NO 2 gas are found to be reversible in nature and the prepared composite film sensors showed good sensitivity with relatively faster response/recovery speeds.


2011 ◽  
Vol 520 (3) ◽  
pp. 932-938 ◽  
Author(s):  
S. Öztürk ◽  
N. Kılınç ◽  
N. Taşaltin ◽  
Z.Z. Öztürk

2017 ◽  
Vol 127 ◽  
pp. 38-46 ◽  
Author(s):  
Dilip L. Kamble ◽  
Namdev S. Harale ◽  
Vithoba L. Patil ◽  
Pramod S. Patil ◽  
Laxman D. Kadam

2018 ◽  
Vol 43 (50) ◽  
pp. 22756-22764 ◽  
Author(s):  
Stanislav Haviar ◽  
Jiří Čapek ◽  
Šárka Batková ◽  
Nirmal Kumar ◽  
Filip Dvořák ◽  
...  

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