Abstract
The effects of radio frequency oxygen plasma treatment on the NH3 gas sensing characteristics of multiwall carbon nanotube (MWCNT)/polyaniline (PANI) composite films are investigated using sensor devices fabricated onto a MEMS micro-hotplate. The Raman and XPS spectra of O2 plasma-treated MWCNTs indicate that oxygenated groups are created on the surface of CNTs after the plasma treatment. These oxygen-containing defects at the surface of plasma-functionalized multiwall carbon nanotubes (pf-MWCNTs) provide a binding site for the PANI, facilitate the CNT-PANI bond, and promote conduction between the MWCNTs and the PANI. The pf-MWCNT/PANI films are found to have a much better linear response and a sensitivity about three times higher than that of a corresponding pristine MWCNT for ammonia concentrations ranging from 0 to 100 ppm. This dramatic improvement in sensing performance may be attributed to the resistance change of the PANI due to deprotonation and the resistance increase of the MWCNTs due to electron transfer from the PANI to the MWCNTs. The pf-MWCNT/PANI films also exhibit a much lower sensitivity to humidity compared with MWCNTs alone. This may be partially due to the reduction of defects on the pf-MWCNT surface available for binding with water molecules, and partially due to opposite sign slope cancellation.
| Original language | English |
|---|---|
| Pages (from-to) | 333-340 |
| Number of pages | 8 |
| Journal | Sensors and Actuators, B: Chemical |
| Volume | 143 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2009 Dec 4 |
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Keywords
- Ammonia gas sensor
- MWCNT
- MWCNT/polymer composite
- Plasma funtionalization
- Polyaniline
ASJC Scopus subject areas
- Instrumentation
- Materials Chemistry
- Surfaces, Coatings and Films
- Metals and Alloys
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
Cite this
Effects of O2 plasma treatment on NH3 sensing characteristics of multiwall carbon nanotube/polyaniline composite films. / Yoo, Kum Pyo; Kwon, Kwang Ho; Min, Nam Ki; Lee, Myong Jin; Lee, Cheol Jin.
In: Sensors and Actuators, B: Chemical, Vol. 143, No. 1, 04.12.2009, p. 333-340.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effects of O2 plasma treatment on NH3 sensing characteristics of multiwall carbon nanotube/polyaniline composite films
AU - Yoo, Kum Pyo
AU - Kwon, Kwang Ho
AU - Min, Nam Ki
AU - Lee, Myong Jin
AU - Lee, Cheol Jin
PY - 2009/12/4
Y1 - 2009/12/4
N2 - The effects of radio frequency oxygen plasma treatment on the NH3 gas sensing characteristics of multiwall carbon nanotube (MWCNT)/polyaniline (PANI) composite films are investigated using sensor devices fabricated onto a MEMS micro-hotplate. The Raman and XPS spectra of O2 plasma-treated MWCNTs indicate that oxygenated groups are created on the surface of CNTs after the plasma treatment. These oxygen-containing defects at the surface of plasma-functionalized multiwall carbon nanotubes (pf-MWCNTs) provide a binding site for the PANI, facilitate the CNT-PANI bond, and promote conduction between the MWCNTs and the PANI. The pf-MWCNT/PANI films are found to have a much better linear response and a sensitivity about three times higher than that of a corresponding pristine MWCNT for ammonia concentrations ranging from 0 to 100 ppm. This dramatic improvement in sensing performance may be attributed to the resistance change of the PANI due to deprotonation and the resistance increase of the MWCNTs due to electron transfer from the PANI to the MWCNTs. The pf-MWCNT/PANI films also exhibit a much lower sensitivity to humidity compared with MWCNTs alone. This may be partially due to the reduction of defects on the pf-MWCNT surface available for binding with water molecules, and partially due to opposite sign slope cancellation.
AB - The effects of radio frequency oxygen plasma treatment on the NH3 gas sensing characteristics of multiwall carbon nanotube (MWCNT)/polyaniline (PANI) composite films are investigated using sensor devices fabricated onto a MEMS micro-hotplate. The Raman and XPS spectra of O2 plasma-treated MWCNTs indicate that oxygenated groups are created on the surface of CNTs after the plasma treatment. These oxygen-containing defects at the surface of plasma-functionalized multiwall carbon nanotubes (pf-MWCNTs) provide a binding site for the PANI, facilitate the CNT-PANI bond, and promote conduction between the MWCNTs and the PANI. The pf-MWCNT/PANI films are found to have a much better linear response and a sensitivity about three times higher than that of a corresponding pristine MWCNT for ammonia concentrations ranging from 0 to 100 ppm. This dramatic improvement in sensing performance may be attributed to the resistance change of the PANI due to deprotonation and the resistance increase of the MWCNTs due to electron transfer from the PANI to the MWCNTs. The pf-MWCNT/PANI films also exhibit a much lower sensitivity to humidity compared with MWCNTs alone. This may be partially due to the reduction of defects on the pf-MWCNT surface available for binding with water molecules, and partially due to opposite sign slope cancellation.
KW - Ammonia gas sensor
KW - MWCNT
KW - MWCNT/polymer composite
KW - Plasma funtionalization
KW - Polyaniline
UR - http://www.scopus.com/inward/record.url?scp=71849107949&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=71849107949&partnerID=8YFLogxK
U2 - 10.1016/j.snb.2009.09.029
DO - 10.1016/j.snb.2009.09.029
M3 - Article
AN - SCOPUS:71849107949
VL - 143
SP - 333
EP - 340
JO - Sensors and Actuators, B: Chemical
JF - Sensors and Actuators, B: Chemical
SN - 0925-4005
IS - 1
ER -