Development of a Strain-Controlled Graphene-Based Highly Sensitive Gas Sensor

Author(s):  
Xiangyu Qiao ◽  
Qinqiang Zhang ◽  
Ken Suzuki

Abstract Small-size wearable multi-gas sensor with high selectivity and sensitivity is demanded for detecting various harmful gases with high sensitivity in chemical plants, various mines, volcanos, oil and gas fields. Graphene is considered to be the most promising gas-sensitive material due to its large specific surface area and high electron mobility. Many studies have shown that it has a high sensitivity to many gases such as NH3, CO, NO2, H2O, and so on. However, the lack of gas selectivity limits the further application of graphene to gas sensing field. In this study, a first-principle calculation was used to investigate the effect of strain on the gas adsorption behavior of graphene. As a result, it was found that the adsorption behavior of H2O and CO molecules was changed by strain. The adsorption energy of both gases increased monotonically with strain. For carbon monoxide molecules, desorption occurred when the applied tensile strain reached about 5%. These analytical results clearly indicated that there is a possibility of the high selectivity of plural gases by applying appropriate critical strain at which its adsorption changes to desorption. To verify this result, the strain-controlled sensor using graphene was developed. The sensor is composed of graphene and electrodes mounted on a deformable substrate. The high-quality graphene is synthesized on copper by LPCVD (low pressure chemical vapor deposition), and then transferred to the PDMS (Polydimethylsiloxane) substrate using PMMA (Poly methyl methacrylate) as a support layer. It was found that the graphene was monolayer and successfully transferred to the target substrate. The effect of strain on the adsorption of some gases was validated by measuring the change of the resistivity of graphene under the application of uniaxial strain.

2005 ◽  
Vol 486-487 ◽  
pp. 485-488 ◽  
Author(s):  
Hong Quang Nguyen ◽  
Mai Van Trinh ◽  
Jeung Soo Huh

The effect of operating temperature on characteristics of single-walled carbon nanotubes (SWNT) based gas sensor was investigated. SWNT-based sensor was fabricated from SWNT powder (Iljin Nanotech, Korea) by screen-printing method. SWNT powder (30 mg, AP grade) was dispersed into 0.78 gram a-terpineol (Aldrich) by ultrasonic vibration for 1 hour then stirred manually for 1 hour to increase adhesion. From this condensed solution, a thick film of SWNT was printed onto alumina substrates. The film then was sintered at 300oC for 2 hours to remove residual impurities. Upon exposure to some gases such as nitrogen, ammonia or nitric oxide, resistance of the sensor dramatically changes due to gas adsorption. In our experiments, SWNT-based sensor was employed to detect NH3 gas in N2 ambience. After saturated of N2, the sensor exposes to NH3 with various concentrations (from 5 ppm to 100 ppm, diluted by N2 as carrier gas). This sensor exhibits a fast response, high sensitivity but slow recovery at room temperature. By heating at high temperature and increasing the flow-rate of carrier gas, NH3 gas desorbs easily and recovery of the sensor improved. The heating also influenced the characteristics of sensors such as response and reproducibility. Other special changes in electric property of SWNT-based sensor caused by heating are also discussed.


2020 ◽  
Vol 65 ◽  
pp. 145-155
Author(s):  
Hadi Riyahi Madvar ◽  
Zoheir Kordrostami ◽  
Samaneh Hamedi

A resistive ethanol gas sensor with a high sensitivity has been proposed. The fabricated gas sensor has a very promising response and recovery at room temperature. The proposed sensor has been fabricated by depositing sensitive nanostructured material on printed circuit board interdigitated electrodes. As the sensitive material, ZnO nanorods of high uniformity have been synthesized by hydrothermal method and then decorated by PbS nanoparticles. The synthesized decorated nanorods were characterized by X-ray diffraction and scanning electron microscope which confirmed the formation of the desired nanostructures. The ethanol gas sensing properties of the ZnO nanorods decorated with PdS nanoparticles was measured in a test chamber. The minimum ethanol concentration detected by the sensor has been 10 ppm. The results showed the higher sensitivity of the proposed sensor to the ethanol at room temperature compared to similar works.


Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7700
Author(s):  
Tingyue Xie ◽  
Ping Wang ◽  
Cuifeng Tian ◽  
Guozheng Zhao ◽  
Jianfeng Jia ◽  
...  

Herein, we have used density functional theory (DFT) to investigate the adsorption behavior of gas molecules on Co/N3 co–doped graphene (Co/N3–gra). We have investigated the geometric stability, electric properties, and magnetic properties comprehensively upon the interaction between Co/N3–gra and gas molecules. The binding energy of Co is −5.13 eV, which is big enough for application in gas adsorption. For the adsorption of C2H4, CO, NO2, and SO2 on Co/N–gra, the molecules may act as donors or acceptors of electrons, which can lead to charge transfer (range from 0.38 to 0.7 e) and eventually change the conductivity of Co/N–gra. The CO adsorbed Co/N3–gra complex exhibits a semiconductor property and the NO2/SO2 adsorption can regulate the magnetic properties of Co/N3–gra. Moreover, the Co/N3–gra system can be applied as a gas sensor of CO and SO2 with high stability. Thus, we assume that our results can pave the way for the further study of gas sensor and spintronic devices.


2020 ◽  
Vol 30 ◽  
pp. 1-7
Author(s):  
Sally K. Abbas ◽  
Asama N. Naje

Functionalized-multi wall carbon nanotubes (F-MWCNTs) and functionalized-single wall carbon nanotubes (F-SWCNTs) were well enhanced using NiO Nanoparticles. The sensor device consisted of a film of sensitive material (F-MWCNTs/ Nickel oxide nanoparticles) and (F-SWCNTs/ Nickel oxide nanoparticles) deposited by drop casting on n-type porous silicon substrate. The two sensors perform high sensitivity to NO2 gas at particular temperatures. The analysis indicated that the (F-MWCNTs/NiONPs) have a better performance than (F-SWCNTs/NiONPs). The F-SWCNTs/NiONPs gas sensor shows high sensitivity (18.2 %) at RT with response time 16 sec, while F-MWCNTs/NiONPs gas sensor show better sensitivity (45 %) at RT with response time 26 sec. The device shows a very reproducible sensor performance, with high repeatability, complete recovery and adequate response. A demonstration of the improvement in sensing of NO2 gas using NiO-functionalized nanotubes is provided.


2020 ◽  
Vol 18 (47) ◽  
pp. 62-72
Author(s):  
Sally K. Abbas ◽  
Asama Natik Naje

Functionalized-multi wall carbon nanotubes (F-MWCNTs) and functionalized-single wall carbon nanotubes (F-SWCNTs) were well enhanced using CoO Nanoparticles. The sensor device consisted of a film of sensitive material (F-MWCNTs/CoONPs) and (F-SWCNTs/CoO NPs) deposited by drop- casting on an n-type porous silicon substrate. The two sensors perform high sensitivity to NO2 gas at room temperatures. The analysis indicated that the (F-MWCNTs/CoONPs) have a better performance than (F-SWCNTs/CoONPs). The F-SWCNTs/CoONPs gas sensor shows high sensitivity (19.1 %) at RT with response time 17 sec, while F-MWCNTs/CoONPs gas sensor show better sensitivity (39 %) at RT with response time 13 sec. The device shows a very reproducible sensor performance, with high repeatability, complete recovery, and adequate response. A demonstration of the improvement in sensing of NO2 gas using CoO-functionalized nanotubes is provided.


2021 ◽  
Vol 9 (7) ◽  
pp. 1811-1820
Author(s):  
Shuang Yan ◽  
Bin Luo ◽  
Jia He ◽  
Fang Lan ◽  
Yao Wu

Novel bimetallic metal–organic framework nanocomposites were fabricated by a facile yet efficient method. The as-prepared nanomaterial exhibited high sensitivity and high selectivity toward phosphopeptides and good reusability of five cycles for enriching phosphopeptides.


2007 ◽  
Vol 124-126 ◽  
pp. 1309-1312
Author(s):  
Nguyen Duc Hoa ◽  
Nguyen Van Quy ◽  
Gyu Seok Choi ◽  
You Suk Cho ◽  
Se Young Jeong ◽  
...  

A new type of gas sensor was realized by directly depositing carbon nanotube on nano channels of the anodic alumina oxide (AAO) fabricated on p-type silicon substrate. The carbon nanotubes were synthesized by thermal chemical vapor deposition at a very high temperature of 1200 oC to improve the crystallinity. The device fabrication process was also developed. The contact of carbon nanotubes and p-type Si substrate showed a Schottky behavior, and the Schottky barrier height increased with exposure to gases while the overall conductivity decreased. The sensors showed fast response and recovery to ammonia gas upon the filling (400 mTorr) and evacuation.


Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 100
Author(s):  
Hongcheng Liu ◽  
Feipeng Wang ◽  
Kelin Hu ◽  
Tao Li ◽  
Yuyang Yan ◽  
...  

In this paper, the Ir-modified MoS2 monolayer is suggested as a novel gas sensor alternative for detecting the characteristic decomposition products of SF6, including H2S, SO2, and SOF2. The corresponding adsorption properties and sensing behaviors were systematically studied using the density functional theory (DFT) method. The theoretical calculation indicates that Ir modification can enhance the surface activity and improve the conductivity of the intrinsic MoS2. The physical structure formation, the density of states (DOS), deformation charge density (DCD), molecular orbital theory analysis, and work function (WF) were used to reveal the gas adsorption and sensing mechanism. These analyses demonstrated that the Ir-modified MoS2 monolayer used as sensing material displays high sensitivity to the target gases, especially for H2S gas. The gas sensitivity order and the recovery time of the sensing material to decomposition products were reasonably predicted. This contribution indicates the theoretical possibility of developing Ir-modified MoS2 as a gas sensor to detect characteristic decomposition gases of SF6.


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