Ultra-Rapid CO Gas Detection by a Gas Sensor Based on Flame-Spray-Made Pt/ZnO Nanoparticles

2009 ◽  
Vol 421-422 ◽  
pp. 332-335 ◽  
Author(s):  
Nittaya Tamaekong ◽  
Chaikarn Liewhiran ◽  
Anurat Wisitsoraat ◽  
Sukon Phanichphant
Keyword(s):  
Zno Nanoparticles ◽  
Gas Sensing ◽  
Zno Nanorods ◽  
Single Step ◽  
Flame Spray ◽  
Al2o3 Substrate ◽  
Particle Properties ◽  
Gas Sensing Properties ◽  
Crystallite Sizes ◽  
20 Nm

ZnO nanoparticles doped with 0.2-2 at.%Pt were successfully produced in a single step by flame spray pyrolysis (FSP) technique using zinc naphthenate and platinum (II) acetylacetonate dissolved in xylene. The particle properties were analyzed by XRD, BET and TEM. Depending on FSP conditions, ZnO nanoparticles and nanorods were observed. The crystallite sizes of ZnO spheroidal particles were found to be ranging from 5 to 20 nm, while ZnO nanorods were seen to be 5-20 nm in width and 20-40 nm in length. ZnO sensing films were prepared using Al2O3 substrate interdigitated with Au electrodes by spin-coating technique. The gas sensing properties toward carbon monoxide (CO) was studied at the operating temperatures ranging from 200 to 350°C. It was found that the 0.2 at.%Pt/ZnO sensing film showed the highest sensitivity and the fastest response time at 350°C.

scholarly journals Structural, Electrical, and Ethanol-Sensing Properties ofLa1-xNdxFeO3Nanoparticles

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Nguyen Thi Thuy ◽  
Dang Le Minh ◽  
Ho Truong Giang ◽  
Nguyen Ngoc Toan
Keyword(s):  
Gas Sensing ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Gel Method ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Crystallite Sizes ◽  
Orthorhombic Perovskite ◽  
Ethanol Sensing ◽  
20 Nm

The nanocrystallineLa1-xNdxFeO3(0≤x ≤1.0) powders with orthorhombic perovskite phase were prepared by sol-gel method. The average crystallite sizes ofLa1-xNdxFeO3powders are about 20 nm. The resistance and gas-sensing properties of theLa1-xNdxFeO3based sensors were investigated in the temperature range from 160 to 300°C. The results demonstrated that the resistance and response of the perovskite thick films changed with the increase of Nd content.

Au sensitized ZnO nanorods for enhanced liquefied petroleum gas sensing properties

2016 ◽  
Vol 371 ◽  
pp. 224-230 ◽  
Author(s):  
U.T. Nakate ◽  
R.N. Bulakhe ◽  
C.D. Lokhande ◽  
S.N. Kale
Keyword(s):  
Gas Sensing ◽  
Zno Nanorods ◽  
Liquefied Petroleum Gas ◽  
Sensing Properties ◽  
Gas Sensing Properties

scholarly journals Nanocrystalline TiO2/SnO2 heterostructures for gas sensing

2017 ◽  
Vol 8 ◽  
pp. 108-122 ◽  
Author(s):  
Barbara Lyson-Sypien ◽  
Anna Kusior ◽  
Mieczylaw Rekas ◽  
Jan Zukrowski ◽  
Marta Gajewska ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Detection Threshold ◽  
Oxygen Adsorption ◽  
Flame Spray ◽  
Nanocrystalline Tio2 ◽  
Water Desorption ◽  
Hydrogen Sensing ◽  
Crystallite Sizes ◽  
Flame Spray Synthesis ◽  
Polymorphic Forms

The aim of this research is to study the role of nanocrystalline TiO2/SnO2 n–n heterojunctions for hydrogen sensing. Nanopowders of pure SnO2, 90 mol % SnO2/10 mol % TiO2, 10 mol % SnO2/90 mol % TiO2 and pure TiO2 have been obtained using flame spray synthesis (FSS). The samples have been characterized by BET, XRD, SEM, HR-TEM, Mössbauer effect and impedance spectroscopy. Gas-sensing experiments have been performed for H2 concentrations of 1–3000 ppm at 200–400 °C. The nanomaterials are well-crystallized, anatase TiO2, rutile TiO2 and cassiterite SnO2 polymorphic forms are present depending on the chemical composition of the powders. The crystallite sizes from XRD peak analysis are within the range of 3–27 nm. Tin exhibits only the oxidation state 4+. The H2 detection threshold for the studied TiO2/SnO2 heterostructures is lower than 1 ppm especially in the case of SnO2-rich samples. The recovery time of SnO2-based heterostructures, despite their large responses over the whole measuring range, is much longer than that of TiO2-rich samples at higher H2 flows. TiO2/SnO2 heterostructures can be intentionally modified for the improved H2 detection within both the small (1–50 ppm) and the large (50–3000 ppm) concentration range. The temperature T max at which the semiconducting behavior begins to prevail upon water desorption/oxygen adsorption depends on the TiO2/SnO2 composition. The electrical resistance of sensing materials exhibits a power-law dependence on the H2 partial pressure. This allows us to draw a conclusion about the first step in the gas sensing mechanism related to the adsorption of oxygen ions at the surface of nanomaterials.

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