The Enhanced H2S Sensing Behavior of Ag-Doped Porous SnO2 Nanopowders Prepared by Template Method

2011 ◽  
Vol 295-297 ◽  
pp. 337-340
Author(s):  
Chao Li ◽  
Hai Yan Xue ◽  
You Qi Zhu ◽  
Yu Ting Wang
Keyword(s):  
Porous Structure ◽  
Catalytic Effect ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Gas Diffusion ◽  
Template Method ◽  
Dramatic Improvement ◽  
Gas Sensing Properties ◽  
Response And Recovery ◽  
Sensing Characteristics

Ag-doped porous SnO2 nanopowders were synthesized via a facile glucan-assisted template method combined with subsequent calcinations. Morphology, crystal structure, and H2S gas sensing properties of pure and Ag-doped porous SnO2 nanopowders were investigated. In comparison with undoped SnO2 nanopowders, the Ag-doped porous SnO2 nanopowders demonstrated enhanced H2S sensing behavior with high sensitivity, short response and recovery time, relatively low response concentration of 50 ppm, and good selectivity. The dramatic improvement in H2S gas sensing characteristics was explained in terms of rapid gas diffusion onto the entire sensing surface due to the less-agglomerated and porous structure of SnO2 nanopowders and the catalytic effect of doped-Ag element. The main objective of this research is to develop a new method to introduce catalysts on gas-sensing materials with less-agglomerated and porous structure.

Preparation and Gas-Sensing Property of Coppertetra-Iso-Propoxyphthalocyanine Spin-Coating Film

2011 ◽  
Vol 197-198 ◽  
pp. 1735-1738
Author(s):  
Qiang Li ◽  
Li Hua Huo ◽  
Shan Gao ◽  
Xiao Juan Qi ◽  
Hui Zhao
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Coating Film ◽  
Gas Sensing Properties ◽  
Response And Recovery ◽  
Ft Ir ◽  
Spinning Speed ◽  
Spectroscopy Property

The thin films of copper 2, 9, 16, 23-tetra-iso-propoxy phthalocyanine (i-pro-CuPc) were prepared by spin-coating technique. The surface morphology and spectroscopy property of the thin films were characterized by AFM, UV-Vis and FT-IR spectra. The results show that good films can be obtained under certain spinning speed. The gas-sensing properties of the multilayers to three alcohols gas were measured at room temperature. The spin-coating thin films exhibited high sensitivity and rapid response- recovery characteristics to these gases. The response and recovery time of the thin films to 30*10-6 v/v of C2H5OH vapor is only 28 s and 55 s, respectively.

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.

Bio-templated fabrication of hierarchically porous WO3 microspheres from lotus pollens for NO gas sensing at low temperatures

RSC Advances ◽  
2015 ◽  
Vol 5 (37) ◽  
pp. 29428-29432 ◽  
Author(s):  
Xiao-Xue Wang ◽  
Kuan Tian ◽  
Hua-Yao Li ◽  
Ze-Xing Cai ◽  
Xin Guo
Keyword(s):  
Porous Structure ◽  
Low Temperatures ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Fast Response ◽  
Hierarchically Porous ◽  
Response And Recovery

Lotus pollen was used as a template to prepare WO3 microspheres. The porous structure of the microspheres is ideal for gas sensing. The microsphere-based sensor has high sensitivity (S = 46.2) to 100 ppm NO gas with fast response and recovery speed 62 s/223 s) at 200 °C.

A Novel Indoor Air Sensor Apply in Detecting Formaldehyde

2020 ◽  
Vol 15 (7) ◽  
pp. 859-863
Author(s):  
Huaiqiu Zhu ◽  
Kaifang Wang ◽  
Fan Zhang ◽  
Wenbin Chen ◽  
Ze Wang ◽  
...  
Keyword(s):  
Indoor Air ◽  
Gas Sensing ◽  
Gas Diffusion ◽  
Sensor Response ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Interior Decoration ◽  
Sensing Material ◽  
Gas Sensing Properties ◽  
Response And Recovery

As an indoor air toxic gas, formaldehyde is the main pollutant in interior decoration. In current work, we reported a novel formaldehyde gas sensing material and its gas sensing properties were investigated. We found that such novel two dimensional structure show excellent gas sensing performance towards formaldehyde and holding the potential of apply in detection of indoor air. Higher sensor response and faster response and recovery speed are primarily responsible for the unique morphology, leading to sufficient sensing reaction on the surface as well as abundant gas diffusion.

Schottky diodes based on 2D materials for environmental gas monitoring: a review on emerging trends, recent developments and future perspectives

2021 ◽  
Author(s):  
Minu Mathew ◽  
Chandra Sekhar Rout
Keyword(s):  
Gas Sensing ◽  
2D Materials ◽  
Schottky Diodes ◽  
High Sensitivity ◽  
Future Perspectives ◽  
Working Temperature ◽  
Emerging Trends ◽  
Gas Sensing Properties ◽  
Recent Developments ◽  
Sensitivity And Selectivity

This review details the fundamentals, working principles and recent developments of Schottky junctions based on 2D materials to emphasize their improved gas sensing properties including low working temperature, high sensitivity, and selectivity.

Polyaniline/SnO2 Nanocomposite Sensor for NO2 Gas Sensing at Low Operating Temperature

2015 ◽  
Vol 14 (04) ◽  
pp. 1550011 ◽  
Author(s):  
A. Sharma ◽  
M. Tomar ◽  
V. Gupta ◽  
A. Badola ◽  
N. Goswami
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
Sensing Properties ◽  
Response Recovery ◽  
Transmission Electron ◽  
Gas Sensing Properties

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.

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.

Gas Sensing Properties of Porous ZnO Nano-Platelet Films

2007 ◽  
Vol 1035 ◽  
Author(s):  
Amandeep Saluja ◽  
Jie Pan ◽  
Lei Kerr ◽  
Eunjung Cho ◽  
Seth Hubbard
Keyword(s):  
Gas Flow ◽  
Room Temperature ◽  
Gas Sensing ◽  
Electrode Spacing ◽  
Porous Films ◽  
Gas Sensitivity ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Response And Recovery ◽  
Carrier Gas Flow

AbstractIn this work, various ZnO nanostructures were synthesized and a detailed study on the effect of different process parameters such as temperature, carrier gas flow, inter-electrode spacing, gas concentration and material properties on gas sensitivity was conducted. Initial ZnO nanoparticles were prepared by a simple solution chemical process and characterized by Secondary Electron Microscopy (SEM) and Brunauer, Emmet and Teller (BET) Sorptometer to demonstrate the morphology and surface area respectively. Sensitivity of nano-platelets and porous films was measured for different concentrations of the analytes (H2, CO). High response was observed at room temperature for H2 gas with sensitivities in excess 80% for 60ppm and about 55% for 80ppm of H2 gas at room temperature were observed for the nano-platelets and the porous films respectively with short response and recovery times of about 200 seconds. The sensitivity of the nano-platelets to CO gas was also measured and found to be about near 90% for 80 ppm CO at operating temperatures of 200 °C.

scholarly journals Discriminable Sensing Response Behavior to Homogeneous Gases Based on n-ZnO/p-NiO Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 785 ◽  
Author(s):  
Wen-Dong Zhou ◽  
Davoud Dastan ◽  
Jing Li ◽  
Xi-Tao Yin ◽  
Qi Wang
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Sol Gel ◽  
High Sensitivity ◽  
Oxide Semiconductor ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
P Type ◽  
Type Response ◽  
Properties Of Composites

Metal oxide semiconductor (MOS) gas sensors have the advantages of high sensitivity, short response-recovery time and long-term stability. However, the shortcoming of poor discriminability of homogeneous gases limits their applications in gas sensors. It is well-known that the MOS materials have similar gas sensing responses to homogeneous gases such as CO and H2, so it is difficult for these gas sensors to distinguish the two gases. In this paper, simple sol–gel method was employed to obtain the ZnO–xNiO composites. Gas sensing performance results illustrated that the gas sensing properties of composites with x > 0.425 showed a p-type response to both CO and H2, while the gas sensing properties of composites with x < 0.425 showed an n-type response to both CO and H2. However, it was interesting that ZnO–0.425NiO showed a p-type response to CO but an discriminable response (n-type) to H2, which indicated that modulating the p-type or n-type semiconductor concentration in p-n composites could be an effective method with which to improve the discriminability of this type of gas sensor regarding CO and H2. The phenomenon of the special gas sensing behavior of ZnO–0.425NiO was explained based on the experimental observations and a range of characterization techniques, including XRD, HRTEM and XPS, in detail.

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