Preparation and Property of Lanthanum Ferrite Formaldehyde Gas Sensor Modified by Carbon Nanotubes and Silver

2013 ◽  
Vol 320 ◽  
pp. 554-557 ◽  
Author(s):  
Yu Min Zhang ◽  
Yu Tao Lin ◽  
Jin Zhang ◽  
Zhong Qi Zhu ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Synthesis ◽  
Recovery Time ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Sol Gel ◽  
Lanthanum Ferrite ◽  
Gas Sensing Properties ◽  
Response And Recovery ◽  
Sensitive Property

Our previous study revealed that the gas sensitive property of Silver-modified Lanthanum Ferrite (Ag-LaFeO3) is well, but the operating temperature is still high and the sensitivity also needs to be improved. This work based on our previous study. Ag-LaFeO3 was further modified by the Carbon nanoTubes (CNTs). The Ag-LaFeO3 powder modified with CNTs (CNTs-Ag-LaFeO3) was prepared by a sol-gel method combined with microwave chemical synthesis. The structure and gas-sensing properties were investigated. The results show that the structure of CNTs-Ag-LaFeO3 is of orthogonal perovskite. The sensitivity of 0.75% CNTs-Ag-LaFeO3 powder for 1 ppm formaldehyde is 13 at 86°C. The response and recovery time are 100s and 60s, respectively. Moreover, the sensor also has an obvious response for 1ppm formaldehyde at 58°C.

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.

Thermal, optical and gas sensing properties of ZnO films prepared by different techniques

2018 ◽  
Vol 81 (1) ◽  
pp. 10101 ◽  
Author(s):  
Sonik Bhatia ◽  
Neha Verma ◽  
Munish Aggarwal
Keyword(s):  
Gas Sensor ◽  
Recovery Time ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
Effect Of Temperature ◽  
Zno Films ◽  
Sensing Properties ◽  
Response And Recovery

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.

TUNGSTEN-DOPED TiO2 NANOLAYERS WITH IMPROVED CO2 GAS SENSING PROPERTIES FOR ENVIRONMENTAL APPLICATIONS

2017 ◽  
Vol 24 (Supp02) ◽  
pp. 1850024 ◽  
Author(s):  
MALIHEH SABERI ◽  
ALI AKBAR ASHKARRAN
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Sol Gel ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Sensing Properties ◽  
Vis Spectroscopy ◽  
Gas Sensing Properties ◽  
Tungsten Concentration

Tungsten-doped TiO2 gas sensors were successfully synthesized using sol–gel process and spin coating technique. The fabricated sensor was characterized by field emission scanning electron microscopy (FE-SEM), ultraviolet visible (UV–Vis) spectroscopy, transmission electron microscopy (TEM), X-Ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Gas sensing properties of pristine and tungsten-doped TiO2 nanolayers (NLs) were probed by detection of CO2 gas. A series of experiments were conducted in order to find the optimum operating temperature of the prepared sensors and also the optimum value of tungsten concentration in TiO2 matrix. It was found that introducing tungsten into the TiO2 matrix enhanced the gas sensing performance. The maximum response was found to be (1.37) for 0.001[Formula: see text]g tungsten-doped TiO2 NLs at 200[Formula: see text]C as an optimum operating temperature.

scholarly journals Enhancement of Gas Sensing Characteristics of Multiwalled Carbon Nanotubes by CF4Plasma Treatment for SF6Decomposition Component Detection

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoxing Zhang ◽  
Xiaoqing Wu ◽  
Bing Yang ◽  
Hanyan Xiao
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Recovery Time ◽  
Treatment Time ◽  
Gas Sensing ◽  
Gas Sensitivity ◽  
Multiwalled Carbon ◽  
State Evaluation ◽  
Response And Recovery ◽  
Sensing Characteristics

H2S and SO2are important gas components of decomposed SF6of partial discharge generated by insulation defects in gas-insulated switchgear (GIS). Therefore, H2S and SO2detection is important in the state evaluation and fault diagnosis of GIS. In this study, dielectric barrier discharge was used to generate CF4plasma and modify multiwalled carbon nanotubes (MWNTs). The nanotubes were plasma-treated at optimum discharge conditions under different treatment times (0.5, 1, 2, 5, 8, 10, and 12 min). Pristine and treated MWNTs were used as gas sensors to detect H2S and SO2. The effects of treatment time on gas sensitivity were analyzed. Results showed that the sensitivity, response, and recovery time of modified MWNTs to H2S were improved, but the recovery time of SO2was almost unchanged. At 10 min treatment time, the MWNTs showed good stability and reproducibility with better gas sensing properties compared with the other nanotubes.

scholarly journals Growth of Defect-Induced Carbon Nanotubes for Low-Temperature Fruit Monitoring Sensor

Chemosensors ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 131
Author(s):  
Nagih M. Shaalan ◽  
Osama Saber ◽  
Faheem Ahmed ◽  
Abdullah Aljaafari ◽  
Shalendra Kumar
Keyword(s):  
Carbon Nanotubes ◽  
Low Temperature ◽  
Recovery Time ◽  
Smooth Surface ◽  
Operating Temperature ◽  
Sensor Response ◽  
Time Constants ◽  
Gas Concentration ◽  
Low Intensity ◽  
Response And Recovery

Herein, a carbon nanotubes-based sensor has been grown for the purpose of ethylene detection. The prepared CNTs had a crystalline structure with a smooth surface of 11.0 nm in diameter and 10.0 µm in length. The low-intensity graphite peak (G-band) as compared to the peak of the defect (D-band) characterizes the defects in the CNTs. An MWNTs-gas sensor was fabricated for monitoring the ethylene gas. The highest response was recorded at a low operating temperature of 30 °C. The sensor was also examined at 300 ppb up to 10 ppm and it showed a response of 2% up to 28%. The sensor response and recovery time constants were varied from 60 to 300 s, depending on the gas concentration. The results that were obtained for the synthetic ethylene gas were also compared with the real measurements for banana ripening. The results confirmed that the sensor is appropriate for the monitoring of fruit ripening.

scholarly journals Gas sensing performance of Sol-gel grown NiO-doped Cr2O3 nanoparticles

2018 ◽  
Vol 16 (37) ◽  
pp. 15-22
Author(s):  
Tunis B. Hassan
Keyword(s):  
Nickel Oxide ◽  
Recovery Time ◽  
Screen Printing ◽  
Gas Sensing ◽  
Sol Gel ◽  
Sensor Element ◽  
Cr2o3 Nanoparticles ◽  
Response And Recovery ◽  
Nh3 Sensor ◽  
Sensing Performance

The sensors based on Nickel oxide doped chromic oxide (NiO: Cr2O3) nanoparticals were fabricated using thick-film screen printing of sol-gel grown powders. The structural, morphological investigations were carried out using XRD, AFM, and FESEM. Furthermore, the gas responsivity were evaluated towards the NH3 and NO2 gas. The NiO0.10: Cr2O3 nanoparticles exhibited excellent response of 95 % at 100oC and better selectivity towards NH3 with low response and recovery time as compared to pure Cr2O3 and can stand as reliable sensor element for NH3 sensor related applications.

scholarly journals Acetone Gas Sensing Properties of a Multiple-Networked Fe2O3-Functionalized CuO Nanorod Sensor

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Sunghoon Park ◽  
Hyejoon Kheel ◽  
Gun-Joo Sun ◽  
Taegyung Ko ◽  
Wan In Lee ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Optimal Operating ◽  
Sensing Properties ◽  
Adsorption Sites ◽  
Gas Sensing Properties ◽  
Response And Recovery ◽  
Cuo Nanorods ◽  
Sensing Performance

Fe2O3-decorated CuO nanorods were prepared by Cu thermal oxidation followed by Fe2O3decoration via a solvothermal route. The acetone gas sensing properties of multiple-networked pristine and Fe2O3-decorated CuO nanorod sensors were examined. The optimal operating temperature of the sensors was found to be 240°C. The pristine and Fe2O3-decorated CuO nanorod sensors showed responses of 586 and 1,090%, respectively, to 1,000 ppm of acetone at 240°C. The Fe2O3-decorated CuO nanorod sensor also showed faster response and recovery than the latter sensor. The acetone gas sensing mechanism of the Fe2O3-decorated CuO nanorod sensor is discussed in detail. The origin of the enhanced sensing performance of the multiple-networked Fe2O3-decorated CuO nanorod sensor to acetone gas was explained by modulation of the potential barrier at the Fe2O3-CuO interface, highly catalytic activity of Fe2O3for acetone oxidation, and the creation of active adsorption sites by Fe2O3nanoparticles.

Room temperature gas sensing properties of tubular hydroxyapatite

2015 ◽  
Vol 39 (5) ◽  
pp. 3865-3874 ◽  
Author(s):  
Li Huixia ◽  
Liu Yong ◽  
Tan Yanni ◽  
Luo Lanlan ◽  
Zhang Qing ◽  
...  
Keyword(s):  
Recovery Time ◽  
Room Temperature ◽  
Gas Sensing ◽  
High Response ◽  
Good Reproducibility ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Response And Recovery

Tubular hydroxyapatite was synthesized and showed high response, selectivity, good reproducibility and short response and recovery time to ammonia.

Gas sensing properties of tin dioxide coated onto multi-walled carbon nanotubes

2006 ◽  
Vol 497 (1-2) ◽  
pp. 355-360 ◽  
Author(s):  
Yan-Li Liu ◽  
Hai-Feng Yang ◽  
Yu Yang ◽  
Zhi-Min Liu ◽  
Guo-Li Shen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Tin Dioxide ◽  
Gas Sensing ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

A facile method for preparation of porous nitrogen-doped Ti Ti3C2Tx MXene for highly responsive acetone detection at high temperature

2021 ◽  
pp. 2151043
Author(s):  
Zijing Wang ◽  
Fen Wang ◽  
Angga Hermawan ◽  
Jianfeng Zhu ◽  
Shu Yin
Keyword(s):  
Gas Sensor ◽  
Recovery Time ◽  
Gas Sensing ◽  
Three Dimensional ◽  
Gas Sensitivity ◽  
Nitrogen Doped ◽  
Dimensional Network ◽  
Potential Applications ◽  
Response And Recovery ◽  
Acetone Detection

Porous nitrogen-doped Ti3C2T[Formula: see text] MXene (N-TCT) with a three-dimensional network structure is synthesized via a simple sacrifice template method and then utilized as an acetone gas sensor. By introducing nitrogen atoms as heteroatoms into Ti3C2T[Formula: see text] nanosheets, some defects generate around the doped nitrogen atoms, which can greatly improve the surface hydrophilicity and adsorption capacity of Ti3C2T[Formula: see text] Mxene nanosheets. It resulted in the enhanced gas sensitivity, achieving a response value of about 36 ([Formula: see text]/[Formula: see text] × 100%) and excellent recovery time (9s) at 150[Formula: see text]C. Compared with the pure Ti3C2T[Formula: see text]-based gas sensor (381/92s), the response and recovery time are both obviously improved, and the response value increased by 3.5 times. The gas-sensing mechanism of the porous N-TCT is also discussed in detail. Based on the excellent gas sensitivity of porous N-TCT for highly responsive acetone detection at high temperatures, the strategy of nitrogen-doped two-dimensional nanomaterials can be extended to other nanomaterials to realize their potential applications.

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