Gas sensitive material on the basis of cholesteric-nematic mixture doped carbon nanotubes for optoelectronic NH3 gas sensor

2017 ◽  
Author(s):  
Vasyl S. Petryshak ◽  
Maria V. Vistak ◽  
Orest Y. Sushynkyi ◽  
Zinoviy M. Mikityuk ◽  
Hryhoriy I. Barylo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Gas Sensor ◽  
Sensitive Material

Room Temperature NO2 Gas Sensor Based on Functionalized Carbon Nanotubes /Nickel Oxide Nanoparticles

2020 ◽  
Vol 30 ◽  
pp. 1-7
Author(s):  
Sally K. Abbas ◽  
Asama N. Naje
Keyword(s):  
Carbon Nanotubes ◽  
Response Time ◽  
Nickel Oxide ◽  
Gas Sensor ◽  
High Sensitivity ◽  
Single Wall Carbon Nanotubes ◽  
Oxide Nanoparticles ◽  
Sensitive Material ◽  
Nickel Oxide Nanoparticles ◽  
Multi Wall Carbon Nanotubes

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.

scholarly journals Enhancement of functionalized carbon nanotubes gas sensor by adding metal oxide nanoparticles

2020 ◽  
Vol 18 (47) ◽  
pp. 62-72
Author(s):  
Sally K. Abbas ◽  
Asama Natik Naje
Keyword(s):  
Carbon Nanotubes ◽  
Response Time ◽  
Gas Sensor ◽  
Metal Oxide Nanoparticles ◽  
High Sensitivity ◽  
Complete Recovery ◽  
Single Wall Carbon Nanotubes ◽  
Sensitive Material ◽  
Multi Wall Carbon Nanotubes ◽  
Sensor Performance

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.

Carbon Nanotube Gas Sensor Fabricated on Anodic Aluminum Oxide

2007 ◽  
Vol 124-126 ◽  
pp. 1309-1312
Author(s):  
Nguyen Duc Hoa ◽  
Nguyen Van Quy ◽  
Gyu Seok Choi ◽  
You Suk Cho ◽  
Se Young Jeong ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Gas Sensor ◽  
Chemical Vapor ◽  
Fast Response ◽  
Device Fabrication ◽  
Alumina Oxide ◽  
Response And Recovery ◽  
New Type ◽  
P Type

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.

Effect of Operating Temperature on Characteristics of Single-Walled Carbon Nanotubes Gas Sensor

2005 ◽  
Vol 486-487 ◽  
pp. 485-488 ◽  
Author(s):  
Hong Quang Nguyen ◽  
Mai Van Trinh ◽  
Jeung Soo Huh
Keyword(s):  
Carbon Nanotubes ◽  
Gas Sensor ◽  
Gas Adsorption ◽  
Operating Temperature ◽  
High Sensitivity ◽  
Single Walled Carbon Nanotubes ◽  
Fast Response ◽  
Carrier Gas ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

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.

Carbon nanotubes coated fiber optic ammonia gas sensor

2011 ◽  
Author(s):  
S. Manivannan ◽  
L. R. Shobin ◽  
A. M. Saranya ◽  
B. Renganathan ◽  
D. Sastikumar ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Gas Sensor ◽  
Fiber Optic ◽  
Ammonia Gas ◽  
Coated Fiber

Fabrication of Carbon Nanotube Gas Sensor Using Step-Wise Dielectrophoretic Deposition Onto Interdigitated Pyrolyzed Carbon Electrodes

2021 ◽  
Author(s):  
Taajza Singleton ◽  
Lawrence Kulinsky
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Gas Sensor ◽  
Carbon Electrodes ◽  
Proof Of Concept ◽  
Nitrogen Gas ◽  
Electrical Field ◽  
The Creation ◽  
Field Lines

Abstract Carbon nanotubes (CNTs) have been implemented in the creation of many micro- and nano-devices due to their physical properties such as large volume-to-surface area as well as their high thermal and electrical conductivity. The paper describes a novel dielectrophoretic step-wise deposition of CNTs (that alternates deposition of CNTs and drying steps) between the interdigitated fingers of carbon electrodes. Multiphysics simulation illustrates the physics of CNT alignment along the electrical field lines that forms a basis for dielectrophoretic deposition of CNTs. This fabrication methodology resulted in the creation of a proof-of-concept nitrogen gas sensor.

Ultrafast NH3 gas sensor based on phthalocyanine-optimized non-covalent hybrid of carbon nanotubes with pyrrole†

2022 ◽  
pp. 131352
Author(s):  
Shijie Gai ◽  
Bin Wang ◽  
Xiaolin Wang ◽  
Runze Zhang ◽  
Shoulei Miao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Gas Sensor

scholarly journals Fully Transparent Gas Sensor Based on Carbon Nanotubes

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4591 ◽  
Author(s):  
Florin C. Loghin ◽  
Aniello Falco ◽  
Jose F. Salmeron ◽  
Paolo Lugli ◽  
Alaa Abdellah ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Gas Sensor ◽  
Active Layer ◽  
Gas Sensors ◽  
Spray Deposition ◽  
Reference Electrode ◽  
Gold Electrodes ◽  
Integrated Sensors ◽  
Reference Sensor ◽  
Higher Sensitivity

In this paper, we demonstrate the feasibility of realization of transparent gas sensors based on carbon nanotubes (CNTs). Both sensing layer and electrodes consist of CNTs deposited by spray deposition. The transparent sensor—with a transmittance higher than 60% in both sensing layer and electrodes—is characterized towards NH3 and CO2 and compared with a reference sensor with the same active layer but evaporated Au electrodes. In particular, the sensitivity towards NH3 is virtually identical for both reference and transparent sensors, whereas the transparent device exhibits higher sensitivity to CO2 than the reference electrode. The effect of the spacing among consecutive electrodes is also studied, demonstrating that a wider spacing in fully CNT based sensors results in a higher sensitivity because of the higher sensing resistance, whereas this effect was not observed in gold electrodes, as their resistance can be neglected with respect to the resistance of the CNT sensing layer. Overall, the transparent sensors show performance comparable—if not superior—to the traditionally realized ones, opening the way for seamlessly integrated sensors, which do not compromise on quality.

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