scholarly journals Enhanced Sensitivity of CO on Two-Dimensional, Strained, and Defective GaSe

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 812
Author(s):  
Hsin-Pan Huang ◽  
Huei-Ru Fuh ◽  
Ching-Ray Chang
Keyword(s):  
Adsorption Energy ◽  
Gas Sensing ◽  
High Surface ◽  
Co Adsorption ◽  
Volume Ratio ◽  
Vacancy Defect ◽  
Unstable State ◽  
Strain Effect ◽  
Two Dimensional ◽  
Human Beings

The toxic gas carbon monoxide (CO) is fatal to human beings and it is hard to detect because of its colorless and odorless properties. Fortunately, the high surface-to-volume ratio of the gas makes two-dimensional (2D) materials good candidates for gas sensing. This article investigates CO sensing efficiency with a two-dimensional monolayer of gallium selenide (GaSe) via the vacancy defect and strain effect. According to the computational results, defective GaSe structures with a Se vacancy have a better performance in CO sensing than pristine ones. Moreover, the adsorption energy gradually increases with the scale of tensile strain in defective structures. The largest adsorption energy reached −1.5 eV and the largest charger transfer was about −0.77 e. Additionally, the CO gas molecule was deeply dragged into the GaSe surface. We conclude that the vacancy defect and strain effect transfer GaSe to a relatively unstable state and, therefore, enhance CO sensitivity. The adsorption rate can be controlled by adjusting the strain scale. This significant discovery makes the monolayer form of GaSe a promising candidate in CO sensing. Furthermore, it reveals the possibility of the application of CO adsorption, transportation, and releasement.

scholarly journals Two-Dimensional Nanomaterials for Gas Sensing Applications: The Role of Theoretical Calculations

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 851 ◽  
Author(s):  
Yamei Zeng ◽  
Shiwei Lin ◽  
Ding Gu ◽  
Xiaogan Li
Keyword(s):  
Electric Fields ◽  
Gas Sensing ◽  
Theoretical Calculations ◽  
High Surface ◽  
Volume Ratio ◽  
Two Dimensional ◽  
Sensing Properties ◽  
Sensing Applications ◽  
Gas Sensing Properties ◽  
2D Nanomaterials

Two-dimensional (2D) nanomaterials have attracted a large amount of attention regarding gas sensing applications, because of their high surface-to-volume ratio and unique chemical or physical gas adsorption capabilities. As an important research method, theoretical calculations have been massively applied in predicting the potentially excellent gas sensing properties of these 2D nanomaterials. In this review, we discuss the contributions of theoretical calculations in the study of the gas sensing properties of 2D nanomaterials. Firstly, we elaborate on the gas sensing mechanisms of 2D layered nanomaterials, such as the traditional charge transfer mechanism, and a standard for distinguishing between physical and chemical adsorption, from the perspective of theoretical calculations. Then, we describe how to conduct a theoretical analysis to explain or predict the gas sensing properties of 2D nanomaterials. Thirdly, we discuss three important methods that have been applied in order to improve the gas sensing properties, that is, defect functionalization (vacancy, edge, grain boundary, and doping), heterojunctions, and electric fields. Among these strategies, theoretical calculations play a very important role in explaining the mechanisms underlying the enhanced gas sensing properties. Finally, we summarize both the advantages and limitations of the theoretical calculations, and present perspectives for further research on the 2D nanomaterials-based gas sensors.

scholarly journals Three-dimensional platinum nanoparticle-based bridges for ammonia gas sensing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nishchay A. Isaac ◽  
Johannes Reiprich ◽  
Leslie Schlag ◽  
Pedro H. O. Moreira ◽  
Mostafa Baloochi ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Response Times ◽  
High Surface ◽  
Three Dimensional ◽  
Performance Testing ◽  
Volume Ratio ◽  
Platinum Nanoparticle ◽  
Ammonia Gas ◽  
Lift Off

AbstractThis study demonstrates the fabrication of self-aligning three-dimensional (3D) platinum bridges for ammonia gas sensing using gas-phase electrodeposition. This deposition scheme can guide charged nanoparticles to predetermined locations on a surface with sub-micrometer resolution. A shutter-free deposition is possible, preventing the use of additional steps for lift-off and improving material yield. This method uses a spark discharge-based platinum nanoparticle source in combination with sequentially biased surface electrodes and charged photoresist patterns on a glass substrate. In this way, the parallel growth of multiple sensing nodes, in this case 3D self-aligning nanoparticle-based bridges, is accomplished. An array containing 360 locally grown bridges made out of 5 nm platinum nanoparticles is fabricated. The high surface-to-volume ratio of the 3D bridge morphology enables fast response and room temperature operated sensing capabilities. The bridges are preconditioned for ~ 24 h in nitrogen gas before being used for performance testing, ensuring drift-free sensor performance. In this study, platinum bridges are demonstrated to detect ammonia (NH3) with concentrations between 1400 and 100 ppm. The sensing mechanism, response times, cross-sensitivity, selectivity, and sensor stability are discussed. The device showed a sensor response of ~ 4% at 100 ppm NH3 with a 70% response time of 8 min at room temperature.

scholarly journals A Review of Carbon Nanotubes-Based Gas Sensors

2009 ◽  
Vol 2009 ◽  
pp. 1-24 ◽  
Author(s):  
Yun Wang ◽  
John T. W. Yeow
Keyword(s):  
Carbon Nanotubes ◽  
Gas Sensors ◽  
Gas Sensing ◽  
Low Cost ◽  
High Surface ◽  
Hollow Structure ◽  
Volume Ratio ◽  
Fast Response ◽  
Sensing Technology ◽  
Structure Of Nanomaterials

Gas sensors have attracted intensive research interest due to the demand of sensitive, fast response, and stable sensors for industry, environmental monitoring, biomedicine, and so forth. The development of nanotechnology has created huge potential to build highly sensitive, low cost, portable sensors with low power consumption. The extremely high surface-to-volume ratio and hollow structure of nanomaterials is ideal for the adsorption of gas molecules. Particularly, the advent of carbon nanotubes (CNTs) has fuelled the inventions of gas sensors that exploit CNTs' unique geometry, morphology, and material properties. Upon exposure to certain gases, the changes in CNTs' properties can be detected by various methods. Therefore, CNTs-based gas sensors and their mechanisms have been widely studied recently. In this paper, a broad but yet in-depth survey of current CNTs-based gas sensing technology is presented. Both experimental works and theoretical simulations are reviewed. The design, fabrication, and the sensing mechanisms of the CNTs-based gas sensors are discussed. The challenges and perspectives of the research are also addressed in this review.

Nanomaterial-based gas sensors used for breath diagnosis

2020 ◽  
Vol 8 (16) ◽  
pp. 3231-3248 ◽  
Author(s):  
Xinyuan Zhou ◽  
Zhenjie Xue ◽  
Xiangyu Chen ◽  
Chuanhui Huang ◽  
Wanqiao Bai ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Gas Sensors ◽  
Active Sites ◽  
Gas Sensing ◽  
High Surface ◽  
Volume Ratio ◽  
Sensing Applications ◽  
Enormous Number

Gas-sensing applications commonly use nanomaterials (NMs) because of their unique physicochemical properties, including a high surface-to-volume ratio, enormous number of active sites, controllable morphology, and potential for miniaturisation.

Analytical modeling of phosphorene-based NO2 gas sensor

2019 ◽  
Vol 33 (14) ◽  
pp. 1950143 ◽  
Author(s):  
Elham Mansouri ◽  
Javad Karamdel ◽  
Mohammad Taghi Ahmadi ◽  
Masoud Berahman
Keyword(s):  
Gas Sensor ◽  
Carrier Mobility ◽  
Analytical Modeling ◽  
Gas Sensing ◽  
High Surface ◽  
Volume Ratio ◽  
Gas Concentration ◽  
Proposed Model ◽  
Gas Sensing Properties ◽  
Acceptable Agreement

Phosphorene is a new two-dimensional material that has great potentials in Nano electronic application, so it has attracted more researchers’ attention nowadays. Indeed, phosphorene is an interesting material in gas sensing, due to its high surface-to-volume ratio and its carrier mobility. Many studies have been reported on phosphorene gas sensing, but there is not enough study on analytical modeling of phosphorene gas sensing properties. In this research, by adopting data from experimental NO2-based gas sensor, an analytical model of the phosphorene gas sensing behavior is presented. Then, the experimental results of NO2 gas sensing are compared with the proposed model and acceptable agreement is reported. This new model is adapted to predict phosphorene gas sensing performance in higher NO2 gas concentrations, which demonstrates, linear relation is established in higher concentrations same as lower ppb NO2 gas concentration. So, we have predicted the result of NO2 gas sensing for higher concentration based on experimental sensing.

scholarly journals 2D Materials for Gas Sensing Applications: A Review on Graphene Oxide, MoS2, WS2 and Phosphorene

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3638 ◽  
Author(s):  
Maurizio Donarelli ◽  
Luca Ottaviano
Keyword(s):  
Graphene Oxide ◽  
Gas Sensing ◽  
2D Materials ◽  
High Surface ◽  
Volume Ratio ◽  
Thick Layer ◽  
Research Field ◽  
First Year ◽  
Sensing Applications ◽  
Recent Developments

After the synthesis of graphene, in the first year of this century, a wide research field on two-dimensional materials opens. 2D materials are characterized by an intrinsic high surface to volume ratio, due to their heights of few atoms, and, differently from graphene, which is a semimetal with zero or near zero bandgap, they usually have a semiconductive nature. These two characteristics make them promising candidate for a new generation of gas sensing devices. Graphene oxide, being an intermediate product of graphene fabrication, has been the first graphene-like material studied and used to detect target gases, followed by MoS2, in the first years of 2010s. Along with MoS2, which is now experiencing a new birth, after its use as a lubricant, other sulfides and selenides (like WS2, WSe2, MoSe2, etc.) have been used for the fabrication of nanoelectronic devices and for gas sensing applications. All these materials show a bandgap, tunable with the number of layers. On the other hand, 2D materials constituted by one atomic species have been synthetized, like phosphorene (one layer of black phosphorous), germanene (one atom thick layer of germanium) and silicone (one atom thick layer of silicon). In this paper, a comprehensive review of 2D materials-based gas sensor is reported, mainly focused on the recent developments of graphene oxide, exfoliated MoS2 and WS2 and phosphorene, for gas detection applications. We will report on their use as sensitive materials for conductometric, capacitive and optical gas sensors, the state of the art and future perspectives.

Semimetallic vanadium molybdenum sulfide for high-performance battery electrodes

2018 ◽  
Vol 6 (20) ◽  
pp. 9411-9419 ◽  
Author(s):  
Qingfeng Zhang ◽  
Longlu Wang ◽  
Jue Wang ◽  
Xinzhi Yu ◽  
Junmin Ge ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Electrode Material ◽  
High Performance ◽  
High Surface ◽  
Volume Ratio ◽  
Lithium Ion ◽  
Diffusion Path ◽  
Molybdenum Sulfide ◽  
Two Dimensional

The ultrathin thickness and lateral morphology of a two dimensional (2D) MoS2 nanosheet contribute to its high surface-to-volume ratio and short diffusion path, rendering it a brilliant electrode material for lithium-ion batteries (LIBs).

scholarly journals Inkjet Printing of Controlled ZnO Nanoparticles Layering

2019 ◽  
Vol 8 (1) ◽  
pp. 34-40
Author(s):  
N. Spinella ◽  
C. Galati ◽  
L. Renna
Keyword(s):  
Zno Nanoparticles ◽  
Gas Sensing ◽  
High Surface ◽  
Volume Ratio ◽  
Specific Chemical ◽  
Force Microscopy ◽  
Electron Microscopies ◽  
Atomic Force ◽  
Preliminary Study

 Controlled layering of functional material can produced a versatile film with specific chemical and physical proprieties for desirable applications. This article presented inkjet multilayer structures of ZnO nanoparticles of specific layer morphology and thickness for the development of devices where a high surface-to-volume ratio is required (e.g. micro gas sensors). Stacked multilayers were stratified through a multi-run printing process suitable to produce large-square pattern on flat silicon support. The formation of a multilayer structure was demonstrate through an extended structural characterization of the resulting film. Printed layer morphology was investigated with optical and scanning electron microscopies; atomic force microscopy profiling characterizations were conducted over the entire printed area to evaluate the pattern reproducibility. Finally, a preliminary study as gas sensing film was performed, using the alcohol/ZnO interaction experiments.

scholarly journals Use of Different Natural Products to Control Growth of Titanium Oxide Nanoparticles in Green Solvent Emulsion, Characterization, and Their Photocatalytic Application

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Eneyew Tilahun Bekele ◽  
Bedasa Abdisa Gonfa ◽  
Fedlu Kedir Sabir
Keyword(s):  
Titanium Oxide ◽  
Organic Dyes ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Polluted Water ◽  
Green Solvents ◽  
Human Beings ◽  
Tio2 Nps ◽  
Synthesis Of Nanoparticles

Water, one of the crucial and the pillar resources to every living thing, could be polluted day to day by different causes such as expansion in industrialization, rapid increment in population size, the threat of climate, and growth of urbanization. The existence of a number of organic dyes, detergents, and pesticides from industrial effluents could lead to severe diseases and even to the death of human beings. Currently, remediation of those hazardous organic contaminants using semiconductor metal oxide catalysts has received extensive attention in recent years. Among the numerous nanometal oxides, titanium oxide (TiO2) nanoparticles (NPs) have been well known as a significant photocatalytic material due to their suitable physiochemical behaviors such as stability, conductivity, high surface area to volume ratio, structure, and porosity nature at the nanoscale level. TiO2 semiconductor nanoparticles could be synthesized via several physiochemical approaches; among those, the biogenic technique is the most selective one which involves the synthesis of NPs using different templates. Biogenic synthesis of nanoparticles is an environmentally friendly protocol that involves the use of different parts and types of biogenic sources such as bacteria, fungi, yeast, virus, and green plants or the byproducts of their metabolism, which act as both reducing and stabilizing agents. TiO2 NPs obtained via the biogenic method provide a potential application for the degradation of organic dyes and other pollutants in wastewater. This method of synthesis of NPs has been given a great attention by researchers due to their nontoxicity, low cost, environmental friendliness, the usage of green solvents, and simplicity of the process. This review focuses on summarizing the synthesis of TiO2 NPs using various biogenic sources, characterization, and their photocatalytic applications for the degradation of different wastes and organic dyes from polluted water.

scholarly journals Improving the ammonia sensing of reduced graphene oxide film by using metal nano-materials

2015 ◽  
Vol 18 (3) ◽  
pp. 72-77
Author(s):  
Hoa Tran My Huynh ◽  
Thu Thi Hoang ◽  
Thanh Thi Phuong Nguyen ◽  
Tham Ngoc Nguyen ◽  
Nhung Thi Tuyet Bui ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Adsorption ◽  
Gas Sensing ◽  
High Surface ◽  
Volume Ratio ◽  
Nano Materials ◽  
Gas Sensitivity ◽  
Ammonia Sensing ◽  
Reduced Graphene

Gas sensing is one of the most promising applications for reduced graphene oxide (rGO). High surface-to-volume ratio in conjunction with remaining reactive oxygen functional groups translates into sensitivity to molecular on the rGO surface. The response of the rGO based devices can be further improved by functionalizing its surface with metal nano-materials. In this paper, we report the ammonia (NH3) sensing behavior of rGO based sensors functionalized with nano-structured metal: silver (Ag) or platinum (Pt) or gold (Au) in air at room temperature and atmospheric pressure. The gas response is detected by the monitoring changes in electrical resistance of the rGO/metal hybrids due to NH3 gas adsorption. Compared to bare rGO, significantly improved NH3 sensitivity is observed with the addition of nano-structured metals. These materials are applied to play the small bridges role connecting many graphene islands together to improve electrical conduction of hybrids while maintaining the inherent advantage of rGO for NH3 gas sensitivity.

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