TY - JOUR
T1 - Selective Detection of Toluene Using Pulse-Driven SnO2Micro Gas Sensors
AU - Suematsu, Koichi
AU - Oyama, Tokiharu
AU - Mizukami, Wataru
AU - Hiroyama, Yuki
AU - Watanabe, Ken
AU - Shimanoe, Kengo
N1 - Funding Information:
This work was partially supported by the Japan Society for the Promotion of Science (JSPS) Grants-in-Aid for Scientific Research (KAKENHI) (JP16H04219, JP17K17941, and JP19K15659) and the Yoshida Foundation for the Promotion of Learning and Education. We thank Figaro Engineering Inc. for partial support and providing the MEMS-type microsensor device. The DFT calculations were performed using the computational facilities in the Research Institute for Information Technology (RIIT) at Kyushu University, Japan. TEM observation was helped by the Advanced Characterization Platform of the Nanotechnology Platform Japan, which is sponsored by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. We thank Editage ( www.editage.com ) for English language editing.
PY - 2020/9/22
Y1 - 2020/9/22
N2 - Improvement of gas selectivity, especially among volatile organic compound (VOC) gases, was attempted by introducing pulse-driven modes in semiconductor gas sensors. The SnO2 microsensor was fabricated on a miniature sensor device constructed with a microheater and electrode. The gas-sensing properties were evaluated under a pulse-driven mode by switching the heater on and off. According to density functional theory calculations and temperature-programmed reaction measurements, toluene molecule, which is one of the VOC gases, was adsorbed on the SnO2 surface by van der Waals forces. The conventional sensor response, Se, defined as the change in the electrical resistance in air and target gas atmosphere, to toluene was four and eight times greater than that to CO and H2, respectively. Moreover, the newly proposed sensor response, Sp, defined as the change in the electrical resistance of the device in the target gas atmosphere during the heater-on period, to toluene was 33 and 29 times greater than that to CO and H2, respectively. This significant difference in the Sp to toluene was caused by the combustion reaction of condensed toluene within the sensing layer. Accordingly, the pulse-driven mode of the semiconductor gas sensor can be exploited to improve the gas selectivity of VOC gases based on these newly defined sensor response measures.
AB - Improvement of gas selectivity, especially among volatile organic compound (VOC) gases, was attempted by introducing pulse-driven modes in semiconductor gas sensors. The SnO2 microsensor was fabricated on a miniature sensor device constructed with a microheater and electrode. The gas-sensing properties were evaluated under a pulse-driven mode by switching the heater on and off. According to density functional theory calculations and temperature-programmed reaction measurements, toluene molecule, which is one of the VOC gases, was adsorbed on the SnO2 surface by van der Waals forces. The conventional sensor response, Se, defined as the change in the electrical resistance in air and target gas atmosphere, to toluene was four and eight times greater than that to CO and H2, respectively. Moreover, the newly proposed sensor response, Sp, defined as the change in the electrical resistance of the device in the target gas atmosphere during the heater-on period, to toluene was 33 and 29 times greater than that to CO and H2, respectively. This significant difference in the Sp to toluene was caused by the combustion reaction of condensed toluene within the sensing layer. Accordingly, the pulse-driven mode of the semiconductor gas sensor can be exploited to improve the gas selectivity of VOC gases based on these newly defined sensor response measures.
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U2 - 10.1021/acsaelm.0c00547
DO - 10.1021/acsaelm.0c00547
M3 - Article
AN - SCOPUS:85093702351
VL - 2
SP - 2913
EP - 2920
JO - ACS Applied Electronic Materials
JF - ACS Applied Electronic Materials
SN - 2637-6113
IS - 9
ER -