Advances in understanding the gas sensing mechanisms by in-situ and operando spectroscopy

2021 ◽  
Author(s):  
Aditya Sharma ◽  
Chandra Sekhar Rout
Keyword(s):  
Gas Sensor ◽  
Gas Sensing ◽  
Active Sensing ◽  
Operando Spectroscopy ◽  
Physiochemical Properties ◽  
Comprehensive Knowledge ◽  
Gas Molecules

Comprehensive knowledge on the gas sensor mechanisms demands a detailed command of the physiochemical properties and features of the active sensing materials and their association with the analyte gas molecules....

scholarly journals The Synthesis of the Pomegranate-Shaped α-Fe2O3 Using an In Situ Corrosion Method of Scorodite and Its Gas-Sensitive Property

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 977
Author(s):  
Wang ◽  
Tang ◽  
Cao ◽  
Chen ◽  
Rong
Keyword(s):  
Iron Oxide ◽  
Gas Sensor ◽  
Potential Application ◽  
Gas Sensing ◽  
Fe2o3 Nanoparticles ◽  
Forming Process ◽  
Gas Sensing Properties ◽  
Sensitive Property ◽  
Research Hotspots

The release of hazardous gas increases with the development of industry. The research of gas-sensitive materials has attracted attention. Nanoscale iron oxide (α-Fe2O3) is one of the research hotspots of gas-sensitive materials because it is a cheap, non-toxic semiconductor material. In this study, pomegranate-shaped α-Fe2O3 was synthesized using an in situ corrosion method of scorodite. Spherical-shaped α-Fe2O3 nanoparticles were included in the octahedral shells. The forming process of the structure was analyzed by a variety of measurements. The shell was formed first through the deposition of Fe(OH)3, which was produced by hydrolyzing scorodite. Then, the corrosion was continued and Fe(OH)3 precipitation was produced below the shell. The particles aggregated and formed spheres. The pomegranate-shaped α-Fe2O3 was formed when the scorodite was hydrolyzed completely. The gas-sensing properties of α-Fe2O3 were investigated. The results showed that pomegranate-shaped α-Fe2O3 was responsive to a variety of gases, especially xylene. The value of Ra/Rg was 67.29 at 340 °C when the concentration of xylene was 1000 ppm. This indicated the pomegranate-shaped α-Fe2O3 has potential application as a xylene gas sensor.

scholarly journals Low-Cost and High-Performance ZnO Nanoclusters Gas Sensor Based on New-Type FTO Electrode for the Low-Concentration H2S Gas Detection

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 435 ◽  
Author(s):  
Guodong Zhao ◽  
Jingyue Xuan ◽  
Xiaolin Liu ◽  
Fuchao Jia ◽  
Yuping Sun ◽  
...  
Keyword(s):  
Gas Sensor ◽  
High Performance ◽  
Gas Sensing ◽  
Low Cost ◽  
Zno Nanorods ◽  
Low Concentration ◽  
New Type ◽  
Zno Nanoclusters ◽  
Fto Glass

A low-cost and high-performance gas sensor was fabricated by the in-situ growing of ZnO nanoclusters (NCs) arrays on the etched fluorine-doped tin dioxide (FTO) glass via a facile dip-coating and hydrothermal method. Etched FTO glass was used as a new-type gas-sensing electrode due to its advantages of being low cost and having excellent thermal and chemical stability. ZnO NCs are composed of multiple ZnO nanorods and can provide adequate lateral contacts to constitute the paths required for the gas-sensing tests simultaneously, which can provide many advantageous point junctions for the detection of low-concentration gases. The gas-sensing tests indicate that the ZnO NCs gas sensor has good selectivity and a high response for the low-concentration H2S gas. The sensing response has reached 3.3 for 500 ppb H2S at 330 °C. The excellent gas-sensing performances should be attributed to the large specific surface area of in-situ grown ZnO NCs, the perfect ohmic contact between ZnO NCs and FTO electrode and the variation of grain boundary barrier at the cross-linked junctions of multiple nanorods. In addition, the detailed effect of work temperature and gas concentration on gas-sensing, the stability of gas sensors and the corresponding response mechanism are also discussed in the present paper.

Synthesis, Characterization, and Gas-Sensing for Trimethylamine of Mesoporous Ni-Doped Indium Oxide

2012 ◽  
Vol 476-478 ◽  
pp. 1264-1267
Author(s):  
Wen Yong Jin ◽  
Yang Cao ◽  
Wei Huang ◽  
Xiao Hong Wang ◽  
Jin Li ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Indium Oxide ◽  
Crystalline Structure ◽  
Gas Sensing ◽  
Sensing Properties

Ni-doped mesoporous indium oxide has been successfully obtained by a simple and effected in-situ nanocasting method. The results characterized indicated that powders had a good crystalline structure, and the synthesis was successfully controlled in nanoscale (meso-structure). The gas sensor based on Ni-doped mesoporous In2O3 exhibit good trimethylamine (TMA) sensing properties, and a possible mechanism was aSubscript textlso provided.

In situ growth of SnO2 nanosheets on a substrate via hydrothermal synthesis assisted by electrospinning and the gas sensing properties of SnO2/polyaniline nanocomposites

RSC Advances ◽  
2016 ◽  
Vol 6 (78) ◽  
pp. 74944-74956 ◽  
Author(s):  
Yang Li ◽  
Huitao Ban ◽  
Mingfei Jiao ◽  
Mujie Yang
Keyword(s):  
Hydrothermal Synthesis ◽  
Gas Sensor ◽  
High Performance ◽  
Gas Sensing ◽  
In Situ Growth ◽  
Sensing Properties ◽  
Gas Sensing Properties

In situ preparation of SnO2 nanosheet/polyaniline composite on a substrate and its applications as a high performance gas sensor.

H2-gas sensing and discriminating actions of a single-yarn sensor based on a Pd/GO multilayered thin film using FFT

2020 ◽  
Vol 12 (27) ◽  
pp. 3537-3544 ◽  
Author(s):  
Pi-Guey Su ◽  
Sheng Lin-Kuo
Keyword(s):  
Thin Film ◽  
Gas Sensor ◽  
Gas Sensing ◽  
Multilayer Thin Film ◽  
Multilayered Thin Film ◽  
Self Assembling ◽  
Single Yarn ◽  
Self Assembled

A single-yarn H2-gas sensor was fabricated by self-assembling Pd/GO/PAH/PSS/PAH/yarn multilayer thin film in situ self-assembled on a single-yarn.

scholarly journals Sensing of NO, NO2, and SO2 on two dimensional WS2 doped with Al, P, and Fe: An ab initio study

2020 ◽  
Author(s):  
jiamu cao ◽  
jing zhou ◽  
jianing shi ◽  
yufeng zhang ◽  
junyu chen ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Gas Sensors ◽  
High Performance ◽  
Density Functional ◽  
Gas Sensing ◽  
Molecular Model ◽  
2D Materials ◽  
State Density ◽  
Two Dimensional ◽  
Gas Molecules

Abstract Owing to their harmful and polluting the environment, nitrogen oxides and sulfur dioxide are expected to monitor when they are used. However, the widespread use of gas sensing methods presents obstacles in terms of portability or stability. Hence, a better detect way needs to be found urgently. The success of graphene-based gas sensors has stimulated interest in two-dimensional (2D) materials in the gas sensing area. Transition metal dichalcogenides (TMDs), such as MoS2 or WS2, are considered to have the high-performance potential for gas sensors. Unfortunately, when used as a gas sensor, the sensing response of the pristine TMDs is greatly affected by a number of gas molecules that are too weak to be detected. Herein, to evaluate the sensing capability of Al, P, and Fe-doped WS2 to NO, NO2, and SO2, the molecular model of the adsorption systems was constructed, and density functional theory (DFT) was used to calculate the adsorption behavior of these gases. The binding force of all the doped-WS2 to the harmful gas molecules is much stronger than that of the pristine WS2. According to the results of adsorption energy, band structure, and state density, Al-doped WS2 has the potential to be used as NO and SO2 gas sensor, while P-doped WS2 is selective to NO. This work opens up a new reference for choosing appropriate doping types on 2D materials for noxious gas sensing.

Metal-oxide based ammonia gas sensors: A review

2020 ◽  
Vol 10 ◽  
Author(s):  
Priya Gupta ◽  
Savita Maurya ◽  
Narendra Kumar Pandey ◽  
Vernica Verma
Keyword(s):  
Metal Oxide ◽  
Metal Oxides ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Review Paper ◽  
Gas Sensing ◽  
Gas Sensitivity ◽  
Ammonia Gas ◽  
Ammonia Sensing ◽  
Ammonia Gas Sensors

: This review paper encompasses a study of metal-oxide and their composite based gas sensors used for the detection of ammonia (NH3) gas. Metal-oxide has come into view as an encouraging choice in the gas sensor industry. This review paper focuses on the ammonia sensing principle of the metal oxides. It also includes various approaches adopted for increasing the gas sensitivity of metal-oxide sensors. Increasing the sensitivity of the ammonia gas sensor includes size effects and doping by metal or other metal oxides which will change the microstructure and morphology of the metal oxides. Different parameters that affect the performances like sensitivity, stability, and selectivity of gas sensors are discussed in this paper. Performances of the most operated metal oxides with strengths and limitations in ammonia gas sensing application are reviewed. The challenges for the development of high sensitive and selective ammonia gas sensor are also discussed.

scholarly journals Millisecond lattice gasification for high-density CO2- and O2-sieving nanopores in single-layer graphene

2021 ◽  
Vol 7 (9) ◽  
pp. eabf0116
Author(s):  
Shiqi Huang ◽  
Shaoxian Li ◽  
Luis Francisco Villalobos ◽  
Mostapha Dakhchoune ◽  
Marina Micari ◽  
...  
Keyword(s):  
Single Layer ◽  
High Density ◽  
Single Layer Graphene ◽  
Pore Density ◽  
Vacancy Defects ◽  
Carbon Gasification ◽  
Layer Graphene ◽  
Gas Molecules ◽  
Good Agreement

Etching single-layer graphene to incorporate a high pore density with sub-angstrom precision in molecular differentiation is critical to realize the promising high-flux separation of similar-sized gas molecules, e.g., CO2 from N2. However, rapid etching kinetics needed to achieve the high pore density is challenging to control for such precision. Here, we report a millisecond carbon gasification chemistry incorporating high density (>1012 cm−2) of functional oxygen clusters that then evolve in CO2-sieving vacancy defects under controlled and predictable gasification conditions. A statistical distribution of nanopore lattice isomers is observed, in good agreement with the theoretical solution to the isomer cataloging problem. The gasification technique is scalable, and a centimeter-scale membrane is demonstrated. Last, molecular cutoff could be adjusted by 0.1 Å by in situ expansion of the vacancy defects in an O2 atmosphere. Large CO2 and O2 permeances (>10,000 and 1000 GPU, respectively) are demonstrated accompanying attractive CO2/N2 and O2/N2 selectivities.

Adsorption of the Gas Molecules (NH3, C2H6O, C3H6O, CO, H2S) on noble metal (Ag, Au, Pt, Pd, Ru)–Doped MoSe2 Monolayer: A First-Principles Study

2021 ◽  
Author(s):  
Lanjuan Zhou ◽  
Sujing Yu ◽  
Yan Yang ◽  
Qi Li ◽  
Tingting Li ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Noble Metal ◽  
First Principles ◽  
Density Functional ◽  
Noble Metals ◽  
Gas Sensing ◽  
Functional Theory ◽  
First Principles Study ◽  
Gas Molecules ◽  
Sensing Performance

In this paper, the effects of five noble metals (Au, Pt, Pd, Ag, Ru) doped MoSe2 on improving gas sensing performance were predicted through density functional theory (DFT) based on...

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