scholarly journals Fabrication of a Miniature Zinc Aluminum Oxide Nanowire Array Gas Sensor and Application for Environmental Monitoring

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Chin-Guo Kuo ◽  
Chi-Wu Huang ◽  
Jung-Hsuan Chen ◽  
Yueh-Han Liu

A miniature n-type semiconductor gas sensor was fabricated successfully using zinc aluminum oxide nanowire array and applied to sense oxygen. The present study provided a novel method to produce zinc aluminum alloy nanowire 80 nm in diameter by the vacuum die casting technique and then obtain zinc aluminum oxide nanowire array using the thermal oxidation technique. The gas sensing properties were evaluated through the change of the sensitivity. The factors influencing the sensitivity of the gas sensor, such as the alloy composition, operating temperature, and oxygen concentration, were investigated further. Experimental results indicated that the maximum sensitivity could be acquired when the weight percentage of aluminum was 5% in zinc aluminum alloy at the operating temperature of200°C.

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Chin-Guo Kuo ◽  
Jung-Hsuan Chen ◽  
Yueh-Han Liu

Zinc aluminum alloy nanowire was fabricated by the vacuum die casting. Zinc aluminum alloy was melted, injected into nanomold under a hydraulic pressure, and solidified as nanowire shape. Nanomold was prepared by etching aluminum sheet with a purity of 99.7 wt.% in oxalic acid solution. A nanochannel within nanomold had a pore diameter of 80 nm and a thickness of 40 μm. Microstructure and characteristic analysis of the alumina nanomold and zinc-aluminum nanowire were performed by scanning electron microscope, X-ray diffraction analysis, and energy dispersive X-ray spectroscopy. Zinc aluminum oxide nanowire array was produced using the thermal oxidation method and designed for the photoelectrode application.


2021 ◽  
Vol 11 (15) ◽  
pp. 6675
Author(s):  
Tran Si Trong Khanh ◽  
Tran Quang Trung ◽  
Le Thuy Thanh Giang ◽  
Tran Quang Nguyen ◽  
Nguyen Dinh Lam ◽  
...  

In this work, the P3HT:rGO:MWCNTs (PGC) nanocomposite film applied to the ammonia gas sensor was successfully fabricated by a drop-casting technique. The results demonstrated that the optimum weight ratio of the PGC nanocomposite gas sensor is 20%:60%:20% as the weight ratio of P3HT:rGO:MWCNTs (called PGC-60). This weight ratio leads to the formation of nanostructured composites, causing the efficient adsorption/desorption of ammonia gas in/out of the film surface. The sensor based on PGC-60 possessed a response time of 30 s, sensitivity up to 3.6% at ammonia gas concentration of 10 ppm, and relative sensitivity of 0.031%/ppm. These results could be attributed to excellent electron transportation of rGO, the main adsorption activator to NH3 gas of P3HT, and holes move from P3HT to the cathodes, which works as charge “nano-bridges” carriers of Multi-Walled Carbon Nanotubes (MWCNTs). In general, these three components of PGC sensors have significantly contributed to the improvement of both the sensitivity and response time in the NH3 gas sensor.


2016 ◽  
Vol 34 (1) ◽  
pp. 204-211 ◽  
Author(s):  
Vishal V. Burungale ◽  
Rupesh S. Devan ◽  
Sachin A. Pawar ◽  
Namdev S. Harale ◽  
Vithoba L. Patil ◽  
...  

AbstractRapid NO2 gas sensor has been developed based on PbS nanoparticulate thin films synthesized by Successive Ionic Layer Adsorption and Reaction (SILAR) method at different precursor concentrations. The structural and morphological properties were investigated by means of X-ray diffraction and field emission scanning electron microscope. NO2 gas sensing properties of PbS thin films deposited at different concentrations were tested. PbS film with 0.25 M precursor concentration showed the highest sensitivity. In order to optimize the operating temperature, the sensitivity of the sensor to 50 ppm NO2 gas was measured at different operating temperatures, from 50 to 200 °C. The gas sensitivity increased with an increase in operating temperature and achieved the maximum value at 150 °C, followed by a decrease in sensitivity with further increase of the operating temperature. The sensitivity was about 35 % for 50 ppm NO2 at 150 °C with rapid response time of 6 s. T90 and T10 recovery time was 97 s at this gas concentration.


Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2483 ◽  
Author(s):  
Siti Mohd Chachuli ◽  
Mohd Hamidon ◽  
Md. Mamat ◽  
Mehmet Ertugrul ◽  
Nor Abdullah

High demand of semiconductor gas sensor works at low operating temperature to as low as 100 °C has led to the fabrication of gas sensor based on TiO2 nanoparticles. A sensing film of gas sensor was prepared by mixing the sensing material, TiO2 (P25) and glass powder, and B2O3 with organic binder. The sensing film was annealed at temperature of 500 °C in 30 min. The morphological and structural properties of the sensing film were characterized by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The gas sensor was exposed to hydrogen with concentration of 100–1000 ppm and was tested at different operating temperatures which are 100 °C, 200 °C, and 300 °C to find the optimum operating temperature for producing the highest sensitivity. The gas sensor exhibited p-type conductivity based on decreased current when exposed to hydrogen. The gas sensor showed capability in sensing low concentration of hydrogen to as low as 100 ppm at 100 °C.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Z. X. Cheng ◽  
X. H. Ren ◽  
J. Q. Xu ◽  
Q. Y. Pan

We present a semiconductor gas sensor based on mesoporous In2O3(m-In2O3). The m-In2O3was successfully fabricated by a simple sol-gel process, using block copolymer PE6800 as a soft template. The results of gas sensing reveal that the m-In2O3prepared at room temperature shows higher resistance, which plays the key role in its greater sensitivity. The pore structure of material has an influence on gas adsorption on the material surface, which further affects response-recovery time of gas sensor.


2018 ◽  
Vol 81 (1) ◽  
pp. 10101 ◽  
Author(s):  
Sonik Bhatia ◽  
Neha Verma ◽  
Munish Aggarwal

Nowadays, for environmental protection, the use of portable gas sensor is essential to detect toxic gases. To control this problem of hazardous gases, metal oxide based sensors plays a vital role. In this recent study, Indium (2 at.wt.%) doped ZnO films has been prepared by sol gel spin coating and thermal evaporation techniques on glass substrates. To enhance the sensing properties, indium (In) was used as dopant and their annealing effect of temperature was observed. Thermal properties have shown the fruitful result that prepared films are useful for the fabrication of solar cell. Electrical properties revealed that capacitance and dielectric constant decreases with increase in frequency. X-ray Diffraction showed hexagonal wurtzite structure highly oriented along (1 0 1) plane. Field emission scanning electron microscope of these synthesis films prepared by different have shown the morphology as nanospheres having size of the order of 40–60 nm. 2.0 at.% of indium as modifier resulted in highest response and selectivity towards 5 ppm of NO2 gas at different operating temperature (50–200 °C). Highest sensitivity was obtained at operating temperature of 150 °C. Prepared films have quick response and recovery time in the range of 14–27 s and 67–63 s. The highest response and recovery time of gas sensor was explained by valence ion mechanism.


2014 ◽  
Vol 492 ◽  
pp. 297-300
Author(s):  
Liu Fang Yang ◽  
Yu Lin Wang ◽  
Qin Hui Wang

Using zinc chloride solution and ammonia (25%) as raw material, with the presence of surfactant (CTAB), the microrod ZnO material was synthesized by the hydrothermal method. The phase composition and microstructure of the prepared ZnO material were characterized with XRD and SEM. The results show that the ZnO material possesses a high degree of crystallization, its diameter below 4 μm, and its length about 35 μm. The gas sensing property of gas sensor fabricated with the prepared ZnO material was evaluated via the static volumetric method. At the operating temperature of 200°C, the gas sensor has high sensitivity and selectivity to CH3COCH3.The gas sensing characterization was also discussed.


2021 ◽  
Vol 16 (1) ◽  
pp. 6-10
Author(s):  
Bo Zuo ◽  
Yan Fu ◽  
Gaofeng Deng ◽  
Lingling Qi

In this work, hierarchical nanorod-assembled ZnO sunflower-like structures were successfully synthesized through a water bath route. Crystalline phase and surface morphology of as-prepared ZnO were investigated via XRD and SEM techniques, respectively. Gas sensor fabricated from nanorod-assembled ZnO sunflowers was made, which exhibits excellent gas sensing properties at various concentrations of acetone and different operating temperatures. The gas response values at the optimum operating temperature (300 °C) are 49 towards 200 ppm acetone. The sensing measurement results indicates that the as-synthesized ZnO material may depict potential application as an acetone detector in asphalt pavement construction.


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