Carbon Nanotube Based Wearable Room Temperature Gas Sensors

Palladium-coated multi-walled carbon nanotube (Pd-MWCNT) nanocomposites have been experimentally proven to show highly improved hydrogen (H2) gas detection characteristics at room temperature when compared with single MWCNTs. In this context, we develop an efficient and convenient method for forming nanocomposites by coating Pd nanoparticles on an MWCNT film. Furthermore, we test the applicability of the nanocomposites as sensing materials in detecting H2 gas at room temperature in a reliable and sensitive manner in contrast with ordinary metal-oxidebased gas sensors that operate at high temperatures. We first study the detection efficacy of the Pd-MWCNT film relative to pure MWCNT film. Subsequently, we investigate the Pd-MWCNT sensor’s sensitivity over time for different gas concentrations, the sensor response time, and sensor reproducibility and reliability under various conditions including bending tests. Our sensor exhibits stable reliable detection characteristics and excellent structural flexibility.

Download Full-text

Room temperature vanadium dioxide–carbon nanotube gas sensors made via continuous hydrothermal flow synthesis

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2017.07.152 ◽

2018 ◽

Vol 255 ◽

pp. 1119-1129 ◽

Cited By ~ 27

Author(s):

Gwyn P. Evans ◽

Michael J. Powell ◽

Ian D. Johnson ◽

Dougal P. Howard ◽

Dustin Bauer ◽

...

Keyword(s):

Carbon Nanotube ◽

Gas Sensors ◽

Vanadium Dioxide ◽

Room Temperature ◽

Flow Synthesis ◽

Hydrothermal Flow

Download Full-text

Highly Sensitive Room-Temperature NO2 Gas Sensors Based on Three-Dimensional Multiwalled Carbon Nanotube Networks on SiO2 Nanospheres

ACS Sustainable Chemistry & Engineering ◽

10.1021/acssuschemeng.0c02707 ◽

2020 ◽

Vol 8 (37) ◽

pp. 13915-13923

Author(s):

Defu Ma ◽

Yanjie Su ◽

Tian Tian ◽

Huan Yin ◽

Tingting Huo ◽

...

Keyword(s):

Carbon Nanotube ◽

Gas Sensors ◽

Room Temperature ◽

Three Dimensional ◽

Multiwalled Carbon Nanotube ◽

Multiwalled Carbon ◽

Highly Sensitive ◽

No2 Gas Sensors ◽

Carbon Nanotube Networks

Download Full-text

Gas Sensing with Solar Cells: The Case of NH3 Detection through Nanocarbon/Silicon Hybrid Heterojunctions

Nanomaterials ◽

10.3390/nano10112303 ◽

2020 ◽

Vol 10 (11) ◽

pp. 2303

Author(s):

Giovanni Drera ◽

Sonia Freddi ◽

Tiziano Freddi ◽

Andrea De Poli ◽

Stefania Pagliara ◽

...

Keyword(s):

Carbon Nanotube ◽

Gas Sensors ◽

Room Temperature ◽

Open Circuit Voltage ◽

Gas Sensing ◽

Open Circuit ◽

Multiwalled Carbon ◽

Single Walled Carbon Nanotube ◽

Cell Parameters ◽

Current Voltage

Photovoltaic (PV) cells based on single-walled carbon nanotube (SWCNT)/silicon (Si) and multiwalled carbon nanotube (MWCNT)/Si junctions were tested under exposure to NH3 in the 0–21 ppm concentration range. The PV cell parameters remarkably changed upon NH3 exposure, suggesting that these junctions, while being operated as PV cells, can react to changes in the environment, thereby acting as NH3 gas sensors. Indeed, by choosing the open-circuit voltage, VOC, parameter as read-out, it was found that these cells behaved as gas sensors, operating at room temperature with a response higher than chemiresistors developed on the same layers. The sensitivity was further increased when the whole current–voltage (I–V) curve was collected and the maximum power values were tracked upon NH3 exposure.

Download Full-text

Porous Indium Oxide Nanotubes: Layer-by-Layer Assembly on Carbon-Nanotube Templates and Application for Room-Temperature NH3 Gas Sensors

Advanced Materials ◽

10.1002/adma.200602128 ◽

2007 ◽

Vol 19 (12) ◽

pp. 1641-1645 ◽

Cited By ~ 326

Author(s):

N. Du ◽

H. Zhang ◽

B. D. Chen ◽

X. Y. Ma ◽

Z. H. Liu ◽

...

Keyword(s):

Carbon Nanotube ◽

Indium Oxide ◽

Gas Sensors ◽

Room Temperature ◽

Layer By Layer ◽

Layer By Layer Assembly ◽

Layer Assembly

Download Full-text

Characteristics of Gas Sensors Based on Single-Walled Carbon Nanotube Bundles Treated by Acid Stirring

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.124-126.1173 ◽

2007 ◽

Vol 124-126 ◽

pp. 1173-1176

Author(s):

Hong Quang Nguyen ◽

Shao Lin Zhang ◽

Gi Hong Rue ◽

Jeung Soo Huh

Keyword(s):

Electron Microscopy ◽

Carbon Nanotube ◽

Gas Sensors ◽

Acid Treatment ◽

Room Temperature ◽

Sem Images ◽

Single Walled Carbon Nanotube ◽

Single Walled Carbon ◽

Transmission Electron ◽

Gas Molecules

The paper presents the effect of acid treatment on the structure of single-walled carbon nanotube (SWNT) bundles and on the characteristics of SWNT-based gas sensors. The commercial SWNT powder was treated with a mixture of concentrated H2SO4:HNO3 (3:1 in volume) before used to fabricate sensors for ammonia (NH3) detection at room temperature. The Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) images indicated that the acid treatment not only removed most of catalytic particles from the SWNT bundles, but also caused SWNT bundles to be fragile. The fracture of the SWNT facilitated for gas molecules to adsorb in the SWNT sites, leading to an enhancement in sensitivity of the sensors. Upon exposing to 50 ppm NH3 in 450 sccm of nitrogen flowing rate at room temperature, the resistance of the 2-h-stirred sensors increased to 38% compared to 22% of the 1-h-stirred sensor. The recovery of the SWNT sensor was also accelerated owing to the treatment. These findings opened a new direction to improve the characteristics of SWNT-based gas sensors.

Download Full-text