Noble metal (Pt or Au)-doped monolayer MoS2 as a promising adsorbent and gas-sensing material to SO2, SOF2 and SO2F2: a DFT study

2018 ◽  
Vol 124 (2) ◽  
Author(s):  
Dachang Chen ◽  
Xiaoxing Zhang ◽  
Ju Tang ◽  
Hao Cui ◽  
Yi Li
Keyword(s):  
Noble Metal ◽  
Gas Sensing ◽  
Dft Study ◽  
Monolayer Mos2 ◽  
Sensing Material

scholarly journals Optimization of a Low-Power Chemoresistive Gas Sensor: Predictive Thermal Modelling and Mechanical Failure Analysis

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 783 ◽  
Author(s):  
Andrea Gaiardo ◽  
David Novel ◽  
Elia Scattolo ◽  
Michele Crivellari ◽  
Antonino Picciotto ◽  
...  
Keyword(s):  
Low Power ◽  
Failure Analysis ◽  
Gas Sensors ◽  
High Performance ◽  
Gas Sensing ◽  
Mechanical Failure ◽  
Sensing Applications ◽  
Theoretical Approaches ◽  
Sensing Material ◽  
Silicon Bulk

The substrate plays a key role in chemoresistive gas sensors. It acts as mechanical support for the sensing material, hosts the heating element and, also, aids the sensing material in signal transduction. In recent years, a significant improvement in the substrate production process has been achieved, thanks to the advances in micro- and nanofabrication for micro-electro-mechanical system (MEMS) technologies. In addition, the use of innovative materials and smaller low-power consumption silicon microheaters led to the development of high-performance gas sensors. Various heater layouts were investigated to optimize the temperature distribution on the membrane, and a suspended membrane configuration was exploited to avoid heat loss by conduction through the silicon bulk. However, there is a lack of comprehensive studies focused on predictive models for the optimization of the thermal and mechanical properties of a microheater. In this work, three microheater layouts in three membrane sizes were developed using the microfabrication process. The performance of these devices was evaluated to predict their thermal and mechanical behaviors by using both experimental and theoretical approaches. Finally, a statistical method was employed to cross-correlate the thermal predictive model and the mechanical failure analysis, aiming at microheater design optimization for gas-sensing applications.

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...

scholarly journals First-Principles Study of Au-Doped InN Monolayer as Adsorbent and Gas Sensing Material for SF6 Decomposed Species

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1708
Author(s):  
Ruochen Peng ◽  
Qu Zhou ◽  
Wen Zeng
Keyword(s):  
Power Systems ◽  
Molecular Orbital ◽  
First Principles ◽  
Recovery Time ◽  
Sulfur Hexafluoride ◽  
Gas Sensing ◽  
Normal Operation ◽  
Frontier Molecular Orbital ◽  
Adsorption System ◽  
Sensing Material

As an insulating medium, sulfur hexafluoride (SF6) is extensively applied to electrical insulation equipment to ensure its normal operation. However, both partial discharge and overheating may cause SF6 to decompose, and then the insulation strength of electrical equipment will be reduced. The adsorption properties and sensing mechanisms of four SF6 decomposed components (HF, SO2, SOF2 and SO2F2) upon an Au-modified InN (Au-InN) monolayer were studied in this work based on first-principles theory. Meanwhile, the adsorption energy (Ead), charge transfer (QT), deformation charge density (DCD), density of states (DOS), frontier molecular orbital and recovery property were calculated. It can be observed that the structures of the SO2, SOF2 and SO2F2 molecules changed significantly after being adsorbed. Meanwhile, the Ead and QT of these three adsorption systems are relatively large, while that of the HF adsorption system is the opposite. These phenomena indicate that Au-InN monolayer has strong adsorption capacity for SO2, SOF2 and SO2F2, and the adsorption can be identified as chemisorption. In addition, through the analysis of frontier molecular orbital, it is found that the conductivity of Au-InN changed significantly after adsorbing SO2, SOF2 and SO2F2. Combined with the analysis of the recovery properties, since the recovery time of SO2 and SO2F2 removal from Au-InN monolayer is still very long at 418 K, Au-InN is more suitable as a scavenger for these two gases rather than as a gas sensor. Since the recovery time of the SOF2 adsorption system is short at 418 K, and the conductivity of the system before and after adsorption changes significantly, Au-InN is an ideal SOF2 gas-sensing material. These results show that Au-InN has broad application prospects as an SO2, SOF2 and SO2F2 scavenger and as a resistive SOF2 sensor, which is of extraordinary meaning to ensure the safe operation of power systems. Our calculations can offer a theoretical basis for further exploration of gas adsorbent and resistive sensors prepared by Au-InN.

Study of Thin Film Tin Oxide for Reliability as Gas Sensing Material

2020 ◽  
Author(s):  
Ravi Shankar ◽  
Tien Choy Loh ◽  
Le Khaing Le ◽  
Chun Wei Khor ◽  
Shian Yeu Kam ◽  
...  
Keyword(s):  
Thin Film ◽  
Tin Oxide ◽  
Gas Sensing ◽  
Sensing Material

Germanene: a new electronic gas sensing material

RSC Advances ◽  
2016 ◽  
Vol 6 (104) ◽  
pp. 102264-102271 ◽  
Author(s):  
Sanjeev K. Gupta ◽  
Deobrat Singh ◽  
Kaptansinh Rajput ◽  
Yogesh Sonvane
Keyword(s):  
Density Functional Theory ◽  
Ab Initio ◽  
Electronic Properties ◽  
Structural Stability ◽  
Density Functional ◽  
Gas Sensing ◽  
Functional Theory ◽  
Adsorption Characteristics ◽  
Sensing Material ◽  
Gas Molecules

The structural stability and electronic properties of the adsorption characteristics of several toxic gas molecules (NH3, SO2 and NO2) on a germanene monolayer were investigated using density functional theory (DFT) based on an ab initio method.

scholarly journals Fabrication of Transition-metal (Zn, Mn, Cu)-based MOFs as Efficient Sensor Materials for Detection of H2 Gas by Clad Modified Fiber Optic Gas Sensor Technique

2021 ◽  
Author(s):  
M Nagoor Meeran ◽  
S.P. Saravanan ◽  
H.H Hegazy
Keyword(s):  
Transition Metal ◽  
Fiber Optic ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Long Term Stability ◽  
Sensing Material ◽  
Sensor Technique ◽  
Recent Developments ◽  
Metal Organic ◽  
Elevated Surface

Abstract Recent research demonstrate that promising gas sensing materials are called metal-organic structures (MOFs) and their products due to their tunable form, elevated surface area, and extremely porous structure and physisorption towards gases with relatively low temperature.In this report, recent developments in transition-metal (Zn, Mn, Cu)-based MOFs and their derivatives are synthesized as sensing materials. The sensors samples were analyzed by XRD, SEM, TEM, BET and XPS in order to know the textural, structural and electronic state of the samples. Fiber optic clad modified sensors were fabricated and tested gas sensing properties towards H2 gas with various concentrations (0-1000 ppm). Among the three sensing material, Zn doped MOFs sensor showed outstanding selectivity with high sensitivity (115 counts/kpa) towards H2 gas. Moreover, it has shown high response (20 s) and recovery time (27 s) as well as long term stability. The designed sensors may be required to apply to the production of an outstanding sensor for H2 for commercial uses.

scholarly journals Light-Excited Ag-Doped TiO2−CoFe2O4 Heterojunction Applied to Toluene Gas Detection

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3261
Author(s):  
Wenhao Wang ◽  
Lu Zhang ◽  
Yanli Kang ◽  
Feng Yu
Keyword(s):  
Diffuse Reflectance ◽  
Gas Sensing ◽  
Limit Of Detection ◽  
Electron Hole ◽  
Detection Range ◽  
Response Recovery ◽  
Test Conditions ◽  
Sensing Material ◽  
Starting Point ◽  
Good Starting Point

(1) Background: Toluene gas is widely used in indoor decoration and industrial production, and it not only pollutes the environment but also poses serious health risks. (2) Methods: In this work, TiO2−CoFe2O4−Ag quaternary composite gas-sensing material was prepared using a hydrothermal method to detect toluene. (3) Results: The recombination of electron–hole pairs was suppressed, and the light absorption range was expanded after constructing a heterojunction and doping with Ag, according to ultraviolet–visible (UV–vis) diffuse reflectance spectra and photoluminescence spectroscopy. Moreover, in the detection range of toluene gas (3 ppm–50 ppm), the response value of TiO2−CoFe2O4−Ag increased from 2 to 15, which was much higher than that of TiO2−Ag (1.7) and CoFe2O4−Ag (1.7). In addition, the working temperature was reduced from 360 °C to 263 °C. Furthermore, its response/recovery time was 40 s/51 s, its limit of detection was as low as 10 ppb, and its response value to toluene gas was 3–7 times greater than that of other interfering gases under the same test conditions. In addition, the response value to 5 ppm toluene was increased from 3 to 5.5 with the UV wavelength of 395 nm–405 nm. (4) Conclusions: This is primarily due to charge flow caused by heterojunction construction, as well as metal sensitization and chemical sensitization of novel metal doping. This work is a good starting point for improving gas-sensing capabilities for the detection of toluene gas.

A Novel Tungsten Trioxide Based Gas Sensor for Indoor Formaldehyde Detection

2021 ◽  
Vol 16 (3) ◽  
pp. 363-367
Author(s):  
Gaoqi Zhang ◽  
Fan Zhang ◽  
Kaifang Wang ◽  
Tao Tian ◽  
Shanyu Liu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Gas Sensor ◽  
Indoor Air ◽  
Gas Sensing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Material ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Gas Response

Accurate and real-time detection of formaldehyde (HCHO) in indoor air is urgently needed for human health. In this work, a ceramic material (WO3·H2O) with unique structure was successfully prepared using an efficient hydrothermal method. The crystallinity, morphology and microstructure of the as-prepared sensing material were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) as well as transmission electron microscope (TEM). The characterization results suggest that the as-prepared sample is composed of square-like nanoplates with uneven surface. Formaldehyde vapor is utilized as the target gas to investigate gas sensing properties of the synthesized novel nanoplates. The testing results indicate that the as-fabricated gas sensor exhibit high gas response and excellent repeatability to HCHO gas. The response value (Ra/Rg) is 24.5 towards 70 ppm HCHO gas at 350 °C. Besides, the gas sensing mechanism was described.

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