scholarly journals Atomistic Descriptions of Gas–Surface Interactions on Tin Dioxide

Chemosensors ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 270
Author(s):  
Stefan Kucharski ◽  
Chris Blackman
Keyword(s):  
Surface Science ◽  
Tin Dioxide ◽  
Gas Sensing ◽  
Computational Modelling ◽  
Adsorption Site ◽  
Ambient Atmosphere ◽  
Experimental Surface ◽  
Spectroscopy Studies ◽  
Gas Surface Interactions ◽  
Reducing Gases

Historically, in gas sensing literature, the focus on “mechanisms” has been on oxygen species chemisorbed (ionosorbed) from the ambient atmosphere, but what these species actually represent and the location of the adsorption site on the surface of the solid are typically not well described. Recent advances in computational modelling and experimental surface science provide insights on the likely mechanism by which oxygen and other species interact with the surface of SnO2, providing insight into future directions for materials design and optimisation. This article reviews the proposed models of adsorption and reaction of oxygen on SnO2, including a summary of conventional evidence for oxygen ionosorption and recent operando spectroscopy studies of the atomistic interactions on the surface. The analysis is extended to include common target and interfering reducing gases, such as CO and H2, cross-interactions with H2O vapour, and NO2 as an example of an oxidising gas. We emphasise the importance of the surface oxygen vacancies as both the preferred adsorption site of many gases and in the self-doping mechanism of SnO2.

scholarly journals Structural Characterization and Gas Sensing Properties of Nano-Sized Tin Dioxide Material Synthesized from Tin(II) Sulfate

2021 ◽  
Vol 66 (9) ◽  
pp. 803
Author(s):  
E. Ovodok ◽  
M. Ivanovskaya ◽  
D. Kotsikau ◽  
V. Kormosh ◽  
P. Pylyp ◽  
...  
Keyword(s):  
Tin Dioxide ◽  
Gas Sensing ◽  
Surface Condition ◽  
Structural Features ◽  
Adsorption Activity ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Concentrated Sulfuric Acid ◽  
Reducing Gases ◽  
Higher Sensitivity

Structural features, surface condition, and gas-sensing properties of the nanocrystalline SnO2 powders synthesized from SnSO4 precursor by different methods have been studied. XRD, TEM, BET, and FTIR methods were used for the samples characterization. The gas sensors were fabricated by the thick-film technology from the synthesized SnO2 powders. The responses of the sensors toward CO and CH4 gases are measured. It is revealed that the preoxidation of SnSO4 powder with concentrated sulfuric acid before the hydrolysis results in the lower particle size, higher surface area, improved adsorption activity, and higher sensitivity to reducing gases (CO, CH4) of the synthesized SnO2 materials, than in the case of the SnO2 materials obtained without the preoxidation stage.

scholarly journals Preparation and Gas Sensing Properties of PANI/SnO2 Hybrid Material

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1360
Author(s):  
Qiaohua Feng ◽  
Huanhuan Zhang ◽  
Yunbo Shi ◽  
Xiaoyu Yu ◽  
Guangdong Lan
Keyword(s):  
Hybrid Material ◽  
Room Temperature ◽  
Tin Dioxide ◽  
Gas Adsorption ◽  
Gas Sensing ◽  
Oxidative Polymerization ◽  
Environmental Pollutants ◽  
Decomposition Temperature ◽  
Benzene Vapor ◽  
Thermo Gravimetric Analyzer

A sensor operating at room temperature has low power consumption and is beneficial for the detection of environmental pollutants such as ammonia and benzene vapor. In this study, polyaniline (PANI) is made from aniline under acidic conditions by chemical oxidative polymerization and doped with tin dioxide (SnO2) at a specific percentage. The PANI/SnO2 hybrid material obtained is then ground at room temperature. The results of scanning electron microscopy show that the prepared powder comprises nanoscale particles and has good dispersibility, which is conducive to gas adsorption. The thermal decomposition temperature of the powder and its stability are measured using a differential thermo gravimetric analyzer. At 20 °C, the ammonia gas and benzene vapor gas sensing of the PANI/SnO2 hybrid material was tested at concentrations of between 1 and 7 ppm of ammonia and between 0.4 and 90 ppm of benzene vapor. The tests show that the response sensitivities to ammonia and benzene vapor are essentially linear. The sensing mechanisms of the PANI/SnO2 hybrid material to ammonia and benzene vapors were analyzed. The results demonstrate that doped SnO2 significantly affects the sensitivity, response time, and recovery time of the PANI material.

Enhanced gas sensing performance of tin dioxide-based nanoparticles for a wide range of concentrations of hydrogen gas

RSC Advances ◽  
2014 ◽  
Vol 4 (36) ◽  
pp. 18512 ◽  
Author(s):  
Pratanu Nag ◽  
Sanhita Majumdar ◽  
Ali Bumajdad ◽  
Parukuttyamma Sujatha Devi
Keyword(s):  
Tin Dioxide ◽  
Gas Sensing ◽  
Hydrogen Gas ◽  
Wide Range ◽  
Sensing Performance

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

Potentiometric Detection of VOCs using Non-Nernstian SmFeO3/Pt/YSZ/Pt Sensors

2006 ◽  
Vol 972 ◽  
Author(s):  
Laure Chevallier ◽  
Elisabetta Di Bartolomeo ◽  
Enrico Traversa ◽  
Masami Mori ◽  
Yoshihiko Sadaoka
Keyword(s):  
Electrochemical Sensors ◽  
Gas Sensing ◽  
Reference Electrode ◽  
Perovskite Oxide ◽  
Potentiometric Detection ◽  
Oxide Powders ◽  
Volatile Organic ◽  
Potentiometric Measurements ◽  
P Type ◽  
Reducing Gases

AbstractElectrochemical sensors for Volatile Organic Compound (VOCs) based on commercial YSZ layers were fabricated using Pt as reference electrode and SmFeO3 perovskite oxide as a sensing electrode, both exposed to the same gas environment. Pt was sputtered on YSZ layers while SmFeO3 p-type semiconducting oxide was deposited by electrophoretic deposition (EPD). Nanometric SmFeO3 oxide powders were selected because they have already shown good sensing performance in semiconducting sensors for oxidizing gases such as NO2 and ozone, and reducing gases, such as VOCs. Potentiometric measurements were performed under exposure to different concentrations of VOCs such as: methyl ethyl ketone (MEK), ethanol (EtOH) and acetic acid (AA). The best gas sensing response was obtained at 400°C.

CHLORINE GAS SENSING OF SnO2 NANOCLUSTERS AS A FUNCTION OF TEMPERATURE: A DFT STUDY

2019 ◽  
Vol 26 (04) ◽  
pp. 1850172
Author(s):  
MUDAR AHMED ABDULSATTAR ◽  
ADEEBH L. RESNE ◽  
SHROK ABDULLAH ◽  
RIYADH J. MOHAMMED ◽  
NOON KADHUM ALARED ◽  
...  
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Density Functional ◽  
Tin Dioxide ◽  
Energy Gap ◽  
Gas Sensing ◽  
Free Energy Calculations ◽  
Measured Temperature ◽  
Chlorine Molecule ◽  
Chlorine Gas

Density functional theory combined with Gibbs free energy calculations is used to study the sensing behavior of tin dioxide (SnO[Formula: see text] clusters towards chlorine gas molecules. Studied SnO2 clusters’ results show the known property of tin dioxide being an oxygen-deficient semiconductor with the preferred stoichiometry SnO[Formula: see text]. The kind of reactions that result in sensing Cl2 molecules is investigated. These include oxygen replacement, chlorine molecule dissociation and van der Waals attachment. Oxygen replacement shows an increase in energy gap which is the case experimentally. Optimum sensing operating temperature towards Cl2 molecules that results from the intersection of the highest SnO2 adsorption and desorption Gibbs free energy lines is at 275∘C in agreement with the experimentally measured temperature of 260∘C.

scholarly journals Electrophoretic deposition of Au NPs on CNT networks for sensitive NO<sub>2</sub> detection

2014 ◽  
Vol 3 (2) ◽  
pp. 245-252 ◽  
Author(s):  
E. Dilonardo ◽  
M. Penza ◽  
M. Alvisi ◽  
C. Di Franco ◽  
D. Suriano ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Spectroscopic Characterization ◽  
Core Diameter ◽  
Au Nps ◽  
Transmission Electron ◽  
P Type ◽  
Reducing Gases ◽  
The Impact

Abstract. In the present study, Au-surfactant core-shell colloidal nanoparticles (NPs) with controlled dimension and composition were synthesized by sacrificial anode electrolysis. Transmission electron microscopy (TEM) revealed that Au NPs core diameter is between 8 and 12 nm, as a function of the electrosynthesis conditions. Moreover, surface spectroscopic characterization by X-ray photoelectron spectroscopy (XPS) analysis confirmed the presence of nanosized gold phase. Controlled amounts of Au NPs were then deposited electrophoretically on carbon nanotube (CNT) networked films. The resulting hybrid materials were morphologically and chemically characterized using TEM, SEM (scanning electron microscopy) and XPS analyses, which revealed the presence of nanoscale gold, and its successful deposition on CNTs. Au NP/CNT networked films were tested as active layers in a two-pole resistive NO2 sensor for sub-ppm detection in the temperature range of 100–200 °C. Au NP/CNT exhibited a p-type response with a decrease in the electrical resistance upon exposure to oxidizing NO2 gas and an increase in resistance upon exposure to reducing gases (e.g. NH3). It was also demonstrated that the sensitivity of the Au NP/CNT-based sensors depends on Au loading; therefore, the impact of the Au loading on gas sensing performance was investigated as a function of the working temperature, gas concentration and interfering gases.

scholarly journals Influence of Mg Doping Levels on the Sensing Properties of SnO2 Films

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2158
Author(s):  
Bouteina Bendahmane ◽  
Milena Tomić ◽  
Nour El Houda Touidjen ◽  
Isabel Gràcia ◽  
Stella Vallejos ◽  
...  
Keyword(s):  
Doping Level ◽  
Tin Dioxide ◽  
Gas Sensing ◽  
Sno2 Film ◽  
Spray Pyrolysis Method ◽  
Composition Analysis ◽  
Ethanol Sensitivity ◽  
Sensing Properties ◽  
Mg Doping ◽  
Mg Doped

This work presents the effect of magnesium (Mg) doping on the sensing properties of tin dioxide (SnO2) thin films. Mg-doped SnO2 films were prepared via a spray pyrolysis method using three doping concentrations (0.8 at.%, 1.2 at.%, and 1.6 at.%) and the sensing responses were obtained at a comparatively low operating temperature (160 °C) compared to other gas sensitive materials in the literature. The morphological, structural and chemical composition analysis of the doped films show local lattice disorders and a proportional decrease in the average crystallite size as the Mg-doping level increases. These results also indicate an excess of Mg (in the samples prepared with 1.6 at.% of magnesium) which causes the formation of a secondary magnesium oxide phase. The films are tested towards three volatile organic compounds (VOCs), including ethanol, acetone, and toluene. The gas sensing tests show an enhancement of the sensing properties to these vapors as the Mg-doping level rises. This improvement is particularly observed for ethanol and, thus, the gas sensing analysis is focused on this analyte. Results to 80 ppm of ethanol, for instance, show that the response of the 1.6 at.% Mg-doped SnO2 film is four times higher and 90 s faster than that of the 0.8 at.% Mg-doped SnO2 film. This enhancement is attributed to the Mg-incorporation into the SnO2 cell and to the formation of MgO within the film. These two factors maximize the electrical resistance change in the gas adsorption stage, and thus, raise ethanol sensitivity.

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