Phase evolution, microstructure, and gas-sensing characteristics of the Sb2O3–Fe2O3 system prepared by coprecipitation

2000 ◽  
Vol 15 (11) ◽  
pp. 2356-2363 ◽  
Author(s):  
Tianshu Zhang ◽  
P. Hing ◽  
Ruifang Zhang ◽  
Jiancheng Zhang ◽  
Young Li
Keyword(s):  
Surface Area ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Phase Evolution ◽  
Antimony Oxide ◽  
Area Measurement ◽  
Crystallite Growth ◽  
Gas Sensitivity ◽  
Experimental Conditions ◽  
Precursor Powders

Precursor powders with antimony-to-iron (Sb/Fe) atomic ratios ranging from 0 to 2.0 were prepared by chemical coprecipitation. The origin of enhanced gas-sensing behavior at a higher calcining temperature was investigated, based on phase evolution and microstructure characterized by means of thermal analysis, x-ray diffraction, Brunauer–Emmett–Teller surface area measurement, and electron microscopy. Only one iron–antimony oxide (i.e., FeSbO4) could be obtained under present experimental conditions. Pure FeSbO4 exhibited a high gas sensitivity, only when calcining temperature was below 600 °C. A rapid crystallite growth, as well as hard agglomeration, occurred in pure FeSbO4 powder calcined at 600–1000 °C, and thus led to poor gas-sensing behavior. However, there existed an optimal Sb/Fe ratio range (i.e., 0.25 to 0.65) in which crystallite growth of both α–Fe2O3 and FeSbO4 could be efficiently depressed up to 800 °C. The samples (with Sb/Fe ratio in the range 0.25–0.65) calcined at 600–800 °C displayed a high sensitivity to liquid petroleum gas due to their large specific surface area and poor crystallinity.

scholarly journals Spatially Ordered Matrix of Nanostructured Tin–Tungsten Oxides Nanocomposites Formed by Ionic Layer Deposition for Gas Sensing

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4169
Author(s):  
Gennady Gorokh ◽  
Natalia Bogomazova ◽  
Abdelhafed Taleb ◽  
Valery Zhylinski ◽  
Timur Galkovsky ◽  
...  
Keyword(s):  
Tungsten Oxide ◽  
Gas Sensing ◽  
Oxide Films ◽  
High Sensitivity ◽  
Anodic Alumina ◽  
Film Deposition ◽  
Silicon Substrates ◽  
Layer By Layer ◽  
Gas Sensitivity ◽  
Nanoporous Anodic Alumina

The process of layer-by-layer ionic deposition of tin-tungsten oxide films on smooth silicon substrates and nanoporous anodic alumina matrices has been studied. To achieve the film deposition, solutions containing cationic SnF2 or SnCl2 and anionic Na2WO4 or (NH4)2O·WO3 precursors have been used. The effect of the solution compositions on the films deposition rates, morphology, composition, and properties was investigated. Possible mechanisms of tin-tungsten oxide films deposition into the pores and on the surface of anodic alumina are discussed. The electro-physical and gas-sensitive properties of nanostructured SnxWyOz films have been investigated. The prepared nanocomposites exhibit stable semiconductor properties characterized by high resistance and low temperature coefficient of electrical resistance of about 1.6 × 10−3 K−1. The sensitivity of the SnxWyOz films to 2 and 10 ppm concentrations of ammonia at 523 K was 0.35 and 1.17, respectively. At concentrations of 1 and 2 ppm of nitrogen dioxide, the sensitivity was 0.48 and 1.4, respectively, at a temperature of 473 K. At the temperature of 573 K, the sensitivity of 1.3 was obtained for 100 ppm of ethanol. The prepared nanostructured tin-tungsten oxide films showed promising gas-sensitivity, which makes them a good candidate for the manufacturing of gas sensors with high sensitivity and low power consumption.

Structural Approach to Improve the Response Characteristics of Copper Phthalocyanine Thin Film-Based NO2Gas Sensor

1997 ◽  
Vol 488 ◽  
Author(s):  
Tadashi Nagasawa ◽  
Kenji Murakami ◽  
Kenzo Watanabe
Keyword(s):  
Copper Phthalocyanine ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Film Deposition ◽  
Gas Sensitivity ◽  
Vacuum Sublimation ◽  
Response Characteristics ◽  
Atomic Force ◽  
Film Microstructure ◽  
Sensing Characteristics

AbstractIn order to realize a high-sensitivity, low temperature operable NO2gas sensor, thin films of at-form copper phthalocyanine (α-CuPc) have been deposited by vacuum sublimation. In this study, we have attempted to improve the gas-sensing characteristics through a modification of the film microstructure. Firstly, the gas sensitivity is remarkably increased by an insertion of higher-sensitive layer (vanadyl Pc film) between the α-CuPc film and the glass substrate in the low gas concentration range. Secondly, a reversibility in cycles of gas doping and dedoping is improved by film deposition on hydrofluoric acid-treated substrate. It is found from atomic force microscope analyses that this phenomenon may be closely related to a modification of the film microstructure.

Synthesis of Mesoporous Polyaniline-TiO2 Composite Microspheres for Gas Sensing Application

2013 ◽  
Vol 750-752 ◽  
pp. 1098-1103 ◽  
Author(s):  
Xiao Lan Song ◽  
Cheng Yin Yan ◽  
Shu Tao Huang ◽  
Ming Wan Zhang ◽  
Bai Yang Geng ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Amorphous State ◽  
High Sensitivity ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
Facile Hydrothermal Method ◽  
Xrd Pattern ◽  
Composite Microspheres ◽  
Ft Ir

The mesoporous polyaniline (PANI)-TiO2composite microspheres were prepared by a facile hydrothermal method and characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) surface area. The XRD pattern suggested that PANI did not modify the crystal structure of TiO2whereas PANI exhibited amorphous state. The SEM of PANI-TiO2displayed for microspheres. The gas sensitivity of the PANI-TiO2hybrid was also studied. The as-prepared sample was sensitivity to ammonia and ethanol and showed good reversibility. The PANI-TiO2hybrid material exhibits high sensitivity (0.96) to ammonia (150ppm) when operates at 373K.

scholarly journals Low-Temperature Synthesis and Gas Sensitivity of Perovskite-Type LaCoO3Nanoparticles

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Lorenzo Gildo Ortiz ◽  
Héctor Guillén Bonilla ◽  
Jaime Santoyo Salazar ◽  
M. de la L. Olvera ◽  
T. V. K. Karthik ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Cobalt Nitrate ◽  
Gas Sensitivity ◽  
Tem Analysis ◽  
Operation Temperature ◽  
Transmission Electron ◽  
Colloidal Method ◽  
Perovskite Type

LaCoO3nanoparticles with perovskite-type structure were prepared by a microwave-assisted colloidal method. Lanthanum nitrate, cobalt nitrate, and ethylenediamine were used as precursors and ethyl alcohol as solvent. The thermal decomposition of the precursors leads to the formation of LaCoO3from a temperature of 500°C. The structural, morphological, and compositional properties of LaCoO3nanoparticles were studied in this work by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). Pellets were manufactured in order to test the gas sensing properties of LaCoO3powders in carbon monoxide (CO) and propane (C3H8) atmospheres. Agglomerates of nanoparticles with high connectivity, forming a porous structure, were observed from SEM and TEM analysis. LaCoO3pellets presented a high sensitivity in both CO and C3H8at different concentrations and operating temperatures. As was expected, sensitivity increased with the gas concentration and operation temperature increase.

scholarly journals Size-controlled synthesis of porous ZnSnO3 nanocubes for improving formaldehyde gas sensitivity

RSC Advances ◽  
2021 ◽  
Vol 11 (33) ◽  
pp. 20268-20277
Author(s):  
Jiaoling Zheng ◽  
Huanhuan Hou ◽  
Hao Fu ◽  
Liping Gao ◽  
Hongjie Liu
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Gas Sensor ◽  
Specific Surface Area ◽  
High Sensitivity ◽  
Controlled Synthesis ◽  
Gas Sensitivity ◽  
Sensitivity And Selectivity ◽  
Size Controlled

The size of the ZnSnO3 nanocubes is about 100 nm with the corresponding specific surface area of 70.001 m2 g−1. A gas sensor based on porous ZnSnO3 nanocubes shows high sensitivity and selectivity to formaldehyde.

Gas Sensing Properties of Tin Oxide Powder Synthesized in the Presence of Surfactants

2005 ◽  
Vol 876 ◽  
Author(s):  
Kiran Jain ◽  
A.K. Srivastava ◽  
R.K. Saxena ◽  
K. Ramesh
Keyword(s):  
Surface Area ◽  
Tin Oxide ◽  
Gas Sensing ◽  
Oxide Powder ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
Compressed Natural Gas ◽  
Transmission Electron ◽  
Liquid Petroleum Gas ◽  
Gas Sensing Properties

AbstractNanocrystalline tin oxide powder was prepared using a solution precipitation technique after adding the surfactant sodium bis (2-ethylhexyl) sulfosuccinate (AOT). Powders were characterized using X-ray diffraction (XRD), surface area (BET) and transmission electron microscopy (TEM). The gas sensitivity for surfactant added powders increased for liquid petroleum gas (LPG) as well as compressed natural gas (CNG), due to the decreased particle size and the increased surface area. The LPG gas sensitivity increased several times using phosphorus treated surfactant AOT.

Synthesis and Gas Sensitivity of SnO2 Nanoparticles

2011 ◽  
Vol 279 ◽  
pp. 93-96
Author(s):  
Zi Feng Ni ◽  
Guo Mei Chen ◽  
Peng Zhan Ying
Keyword(s):  
Tin Dioxide ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Gas Sensitivity ◽  
Rutile Structure ◽  
X Ray ◽  
Tetragonal Rutile Structure ◽  
Sensitivity And Selectivity

Tin dioxide (SnO2) nanoparticles have been synthesized in bulk quantity by thermal evaporation of SnO powder. The x-ray powder diffraction (XRD) analysis indicates that the nanoparticles are the tetragonal rutile structure of SnO2. Scanning electron microscopy (SEM) analysis shows that the size of the synthesized SnO2 nanoparticles is relatively homogeneous with diameter of about 10 nm. Gas-sensing components have been manufactured with the SiO2 nanoparticles. Their performances indicate that it has high sensitivity and selectivity to LPG, and the max sensitivity appears at 280°C, compared with C2H5OH, H2, CO and CH4.

Preparation of Polyaniline/Cu-BTC Composite and its Sensing Application for Ammonia

2017 ◽  
Vol 748 ◽  
pp. 353-357
Author(s):  
Yong Jin Zou ◽  
Ying Yin ◽  
Hai Tao Zhang ◽  
Fen Xu ◽  
Li Xian Sun
Keyword(s):  
Surface Area ◽  
Room Temperature ◽  
Gas Sensing ◽  
High Surface ◽  
Hydrothermal Process ◽  
High Surface Area ◽  
High Sensitivity ◽  
Pani Composite ◽  
Sensing Application ◽  
Sensing Performance

In this study, a newly materials based on copper–benzene-1,3,5-tricarboxylate/polyaniline (PANI/Cu-BTC) composite was investigated for NH3 sensing. Cu-BTC was grown on the PANI a hydrothermal process. The sensing performance of as-grown product was studied for different concentrations of NH3 at room temperature. The results reveal that Cu-BTC/PANI composite exhibit high sensitivity toward NH3. The good sensing performance of the composite was attributed to high surface area and good affinity of Cu-BTC for NH3, which can act like preconcentrator for the NH3 gas sensing.

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.

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