TY - JOUR
T1 - Highly Sensitive Carbon Monoxide Sensor Element with Wide-Range Humidity Resistance by Loading Pd Nanoparticles on SnO2 Surface
AU - Suematsu, Koichi
AU - Uchiyama, Akihito
AU - Watanabe, Ken
AU - Shimanoe, Kengo
N1 - Funding Information:
Author Contributions: Conceptualization, K.S. (Kengo Shimanoe); methodology, K.S. (Koichi Suematsu) and K.W.; validation, A.U., K.S. (Koichi Suematsu), and K.W.; investigation, A.U.; writing—original draft preparation, K.S. (Koichi Suematsu); visualization, A.U. and K.S. (Koichi Acknowledgments: The authors thank the Fukuoka Industrial Technology Center for WDX analysis. This work was partially supported by FIGARO Engineering Inc. K. Suematsu was partially supported by the Paloma environmental technology development foundation.
Funding Information:
This research was funded in part by JSPS KAKENHI, grant numbers JP19H02437 and JP19K15659. This research was partially supported by the Initiative for Realizing Diversity in the Research Environment.
Publisher Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2022/4/1
Y1 - 2022/4/1
N2 - To develop a highly sensitive carbon monoxide (CO) sensor with a wide range of humidity resistance, we focused on the Pd loading method on SnO2 nanoparticles and the thickness of the sensing layer. The Pd nanoparticles were loaded on the SnO2 surface using the surface immobilization method (SI-Pd/SnO2) and the colloidal protection method (CP-Pd/SnO2). The XPS analysis indicated that the Pd nanoparticles were a composite of PdO and Pd, regardless of the loading method. According to the evaluation of the electrical properties at 350 °C, the CO response in a humid atmosphere and the resistance toward humidity change using CP-Pd/SnO2 were higher than those using SI-Pd/SnO2, even though the Pd loading amount of SI-Pd/SnO2 was slightly larger than that of CP-Pd/SnO2. In addition, Pd/SnO2 prepared via the CP method with a thinner sensing layer showed a higher sensor response and greater stability to humidity changes at 300 °C, even though the humidity change influenced the CO response at 250 and 350 °C. Thus, the overall design of the surface Pd, including size, dispersity, and oxidation state, and the sensor fabrication, that is, the thickness of the sensing layer, offer a high-performance semiconductor-type CO gas sensor with a wide range of humidity resistance.
AB - To develop a highly sensitive carbon monoxide (CO) sensor with a wide range of humidity resistance, we focused on the Pd loading method on SnO2 nanoparticles and the thickness of the sensing layer. The Pd nanoparticles were loaded on the SnO2 surface using the surface immobilization method (SI-Pd/SnO2) and the colloidal protection method (CP-Pd/SnO2). The XPS analysis indicated that the Pd nanoparticles were a composite of PdO and Pd, regardless of the loading method. According to the evaluation of the electrical properties at 350 °C, the CO response in a humid atmosphere and the resistance toward humidity change using CP-Pd/SnO2 were higher than those using SI-Pd/SnO2, even though the Pd loading amount of SI-Pd/SnO2 was slightly larger than that of CP-Pd/SnO2. In addition, Pd/SnO2 prepared via the CP method with a thinner sensing layer showed a higher sensor response and greater stability to humidity changes at 300 °C, even though the humidity change influenced the CO response at 250 and 350 °C. Thus, the overall design of the surface Pd, including size, dispersity, and oxidation state, and the sensor fabrication, that is, the thickness of the sensing layer, offer a high-performance semiconductor-type CO gas sensor with a wide range of humidity resistance.
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U2 - 10.3390/s22082934
DO - 10.3390/s22082934
M3 - Article
C2 - 35458919
AN - SCOPUS:85127984153
VL - 22
JO - Sensors
JF - Sensors
SN - 1424-3210
IS - 8
M1 - 2934
ER -