scholarly journals Gallium Nitride (GaN) Nanostructures and Their Gas Sensing Properties: A Review

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3889 ◽  
Author(s):  
Md Ashfaque Hossain Khan ◽  
Mulpuri V. Rao
Keyword(s):  
Density Functional ◽  
Gas Sensing ◽  
Limit Of Detection ◽  
Performance Comparison ◽  
Machine Learning Algorithms ◽  
Sensing Applications ◽  
Ethanol Sensing ◽  
Carbon Dioxide Co2 ◽  
Nanostructured Sensors ◽  
Sensing Performance

In the last two decades, GaN nanostructures of various forms like nanowires (NWs), nanotubes (NTs), nanofibers (NFs), nanoparticles (NPs) and nanonetworks (NNs) have been reported for gas sensing applications. In this paper, we have reviewed our group’s work and the works published by other groups on the advances in GaN nanostructures-based sensors for detection of gases such as hydrogen (H2), alcohols (R-OH), methane (CH4), benzene and its derivatives, nitric oxide (NO), nitrogen dioxide (NO2), sulfur-dioxide (SO2), ammonia (NH3), hydrogen sulfide (H2S) and carbon dioxide (CO2). The important sensing performance parameters like limit of detection, response/recovery time and operating temperature for different type of sensors have been summarized and tabulated to provide a thorough performance comparison. A novel metric, the product of response time and limit of detection, has been established, to quantify and compare the overall sensing performance of GaN nanostructure-based devices reported so far. According to this metric, it was found that the InGaN/GaN NW-based sensor exhibits superior overall sensing performance for H2 gas sensing, whereas the GaN/(TiO2–Pt) nanowire-nanoclusters (NWNCs)-based sensor is better for ethanol sensing. The GaN/TiO2 NWNC-based sensor is also well suited for TNT sensing. This paper has also reviewed density-functional theory (DFT)-based first principle studies on the interaction between gas molecules and GaN. The implementation of machine learning algorithms on GaN nanostructured sensors and sensor array has been analyzed as well. Finally, gas sensing mechanism on GaN nanostructure-based sensors at room temperature has been discussed.

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 Antiresonant Hollow-Core Fiber-Based Dual Gas Sensor for Detection of Methane and Carbon Dioxide in the Near- and Mid-Infrared Regions

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3813 ◽  
Author(s):  
Piotr Jaworski ◽  
Paweł Kozioł ◽  
Karol Krzempek ◽  
Dakun Wu ◽  
Fei Yu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Gas Sensor ◽  
Gas Sensing ◽  
Simultaneous Detection ◽  
Hollow Core ◽  
Mid Infrared ◽  
Sensing Applications ◽  
Core Fiber ◽  
Sensor Configuration ◽  
Carbon Dioxide Co2

In this work, we present for the first time a laser-based dual gas sensor utilizing a silica-based Antiresonant Hollow-Core Fiber (ARHCF) operating in the Near- and Mid-Infrared spectral region. A 1-m-long fiber with an 84-µm diameter air-core was implemented as a low-volume absorption cell in a sensor configuration utilizing the simple and well-known Wavelength Modulation Spectroscopy (WMS) method. The fiber was filled with a mixture of methane (CH4) and carbon dioxide (CO2), and a simultaneous detection of both gases was demonstrated targeting their transitions at 3.334 µm and 1.574 µm, respectively. Due to excellent guidance properties of the fiber and low background noise, the proposed sensor reached a detection limit down to 24 parts-per-billion by volume for CH4 and 144 parts-per-million by volume for CO2. The obtained results confirm the suitability of ARHCF for efficient use in gas sensing applications for over a broad spectral range. Thanks to the demonstrated low loss, such fibers with lengths of over one meter can be used for increasing the laser-gas molecules interaction path, substituting bulk optics-based multipass cells, while delivering required flexibility, compactness, reliability and enhancement in the sensor’s sensitivity.

Enhanced photoconductivity of a polyoxometalate–TiO2 composite for gas sensing applications

2015 ◽  
Vol 3 (24) ◽  
pp. 6153-6157 ◽  
Author(s):  
Zhixia Sun ◽  
Yuzhuo Zhang ◽  
Na Li ◽  
Lin Xu ◽  
Tianqi Wang
Keyword(s):  
Gas Sensing ◽  
Sensing Applications ◽  
Sensing Performance

The polyoxometalates and TiO2 composite displayed better photoconductivity and gas sensing performance for acetone than pristine TiO2.

Polymer Coated Microfabricated Interdigitated Electrodes Arrays for Gas Sensing Applications

2011 ◽  
Vol 495 ◽  
pp. 87-90
Author(s):  
P. Oikonomou ◽  
K. Manoli ◽  
D. Goustouridis ◽  
A. Botsialas ◽  
E. Valamontes ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Sensor Arrays ◽  
Interdigitated Electrodes ◽  
Sensing Applications ◽  
Quartz Substrates ◽  
Sensing Performance

InterDigitated Capacitive (IDC) sensor arrays are fabricated with conventional microelectronics-micromachining technologies on quartz substrates. After fabrication, a polymeric well is patterned around each IDC to precisely define the sensing area and thus deposit coatings of various polymers, by drop casting, in a reproducible and controlled manner. The gas sensing performance of the IDC array is presented for humidity and p-xylene.

scholarly journals Mg-doped and chemo-thermally treated ZnO nanoflowers for ethanol sensing

2021 ◽  
Author(s):  
Santanu Maity ◽  
P.P Sahu ◽  
Tiju Thomas
Keyword(s):  
Gas Sensing ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Applications ◽  
Wide Range ◽  
Doped Zno ◽  
Ethanol Sensing ◽  
Better Than ◽  
Mg Doped

Abstract ZnO nanostructures are promising for a wide range of applications, including gas sensors. Ethanol sensing using ZnO remains unexplored though. In this paper, we report ethanol-sensing using un-doped ZnO nano flowers and Mg doped ZnO nano flowers. These are grown using a rather simple chemo-thermal process, making this a plausibly scalable technology. To study the structural and morphological properties of undoped ZnO and Mg doped ZnO nanoflowers, Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), x-ray diffraction and Field Emission Scanning Electron Microscopy (FESEM) are carried out. Ethanol sensing properties of undoped ZnO and Mg doped ZnO nanoflower devices are investigated toward different ethanol concentration (concentration range of 1–600 ppm at 100°C–200°C). Our findings show that 15% Mg doped ZnO nano flower is better than ZnO nano flower for ethanol gas-sensing applications.

scholarly journals High-Performance Gas Sensor of Polyaniline/Carbon Nanotube Composites Promoted by Interface Engineering

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 149 ◽  
Author(s):  
Weiyu Zhang ◽  
Shuai Cao ◽  
Zhaofeng Wu ◽  
Min Zhang ◽  
Yali Cao ◽  
...  
Keyword(s):  
High Performance ◽  
Structural Changes ◽  
Gas Sensing ◽  
Response Times ◽  
Limit Of Detection ◽  
Hierarchical Structures ◽  
Cost Effective ◽  
One Dimensional ◽  
P Type ◽  
Sensing Performance

Inspired by the enhanced gas-sensing performance by the one-dimensional hierarchical structure, one-dimensional hierarchical polyaniline/multi-walled carbon nanotubes (PANI/CNT) fibers were prepared. Interestingly, the simple heating changed the sensing characteristics of PANI from p-type to n-type and n-type PANI and p-type CNTs form p–n hetero junctions at the core–shell interface of hierarchical PANI/CNT composites. The p-type PANI/CNT (p-PANI/CNT) and n-type PANI/CNT (n-PANI/CNT) performed the higher sensitivity to NO2 and NH3, respectively. The response times of p-PANI/CNT and n-PANI/CNT to 50 ppm of NO2 and NH3 are only 5.2 and 1.8 s, respectively, showing the real-time response. The estimated limit of detection for NO2 and NH3 is as low as to 16.7 and 6.4 ppb, respectively. After three months, the responses of p-PANI/CNT and n-PANI/CNT decreased by 19.1% and 11.3%, respectively. It was found that one-dimensional hierarchical structures and the deeper charge depletion layer enhanced by structural changes of PANI contributed to the sensitive and fast responses to NH3 and NO2. The formation process of the hierarchical PANI/CNT fibers, p–n transition, and the enhanced gas-sensing performance were systematically analyzed. This work also predicts the development prospects of cost-effective, high-performance PANI/CNT-based sensors.

scholarly journals Gas sensing performance at room temperature of nanogap interdigitated electrodes for detection of acetone at low concentration

RSC Advances ◽  
2017 ◽  
Vol 7 (79) ◽  
pp. 50279-50286 ◽  
Author(s):  
Q. Nguyen Minh ◽  
H. D. Tong ◽  
A. Kuijk ◽  
F. van de Bent ◽  
P. Beekman ◽  
...  
Keyword(s):  
Large Scale ◽  
Room Temperature ◽  
Gas Sensing ◽  
Fabrication Technology ◽  
Micro Fabrication ◽  
Interdigitated Electrodes ◽  
Low Concentration ◽  
Sensing Applications ◽  
Nanogap Electrodes ◽  
Sensing Performance

A facile approach for the fabrication of large-scale interdigitated nanogap electrodes (nanogap IDEs) with a controllable gap was demonstrated with conventional micro-fabrication technology to develop chemocapacitors for gas sensing applications.

scholarly journals Recent Advances in Electrochemical Sensors for Detecting Toxic Gases: NO2, SO2 and H2S

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 905 ◽  
Author(s):  
Md Khan ◽  
Mulpuri Rao ◽  
Qiliang Li
Keyword(s):  
Metal Oxide ◽  
Gas Sensors ◽  
Electrochemical Sensors ◽  
Gas Sensing ◽  
Performance Comparison ◽  
Toxic Gases ◽  
Recent Advances ◽  
Metal Metal ◽  
Sensor Materials ◽  
Sensing Performance

Toxic gases, such as NOx, SOx, H2S and other S-containing gases, cause numerous harmful effects on human health even at very low gas concentrations. Reliable detection of various gases in low concentration is mandatory in the fields such as industrial plants, environmental monitoring, air quality assurance, automotive technologies and so on. In this paper, the recent advances in electrochemical sensors for toxic gas detections were reviewed and summarized with a focus on NO2, SO2 and H2S gas sensors. The recent progress of the detection of each of these toxic gases was categorized by the highly explored sensing materials over the past few decades. The important sensing performance parameters like sensitivity/response, response and recovery times at certain gas concentration and operating temperature for different sensor materials and structures have been summarized and tabulated to provide a thorough performance comparison. A novel metric, sensitivity per ppm/response time ratio has been calculated for each sensor in order to compare the overall sensing performance on the same reference. It is found that hybrid materials-based sensors exhibit the highest average ratio for NO2 gas sensing, whereas GaN and metal-oxide based sensors possess the highest ratio for SO2 and H2S gas sensing, respectively. Recently, significant research efforts have been made exploring new sensor materials, such as graphene and its derivatives, transition metal dichalcogenides (TMDs), GaN, metal-metal oxide nanostructures, solid electrolytes and organic materials to detect the above-mentioned toxic gases. In addition, the contemporary progress in SO2 gas sensors based on zeolite and paper and H2S gas sensors based on colorimetric and metal-organic framework (MOF) structures have also been reviewed. Finally, this work reviewed the recent first principle studies on the interaction between gas molecules and novel promising materials like arsenene, borophene, blue phosphorene, GeSe monolayer and germanene. The goal is to understand the surface interaction mechanism.

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