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S&M1278 Research Paper of Special Issue https://doi.org/10.18494/SAM.2016.1396 Published: November 16, 2016 Analysis of Recovery Time of Pt-, Pd-, and Au-Loaded SnO2 Sensor Material with Nonanal as Large-Molecular-Weight Volatile Organic Compounds [PDF] Toshio Itoh, Daiheon Lee, Tomoyo Goto, Takafumi Akamatsu, Noriya Izu, Woosuck Shin, and Toshihiro Kasuga (Received April 25, 2016; Accepted July 26, 2016) Keywords: volatile organic compounds (VOCs), nonanal, Pt-, Pd-, and Au-loaded SnO2, temperatureprogrammedreaction (TPRe), aging, recovery time
We investigated the recovery times of Pt-, Pd-, and Au-loaded SnO2 (Pt, Pd, Au/SnO2) semiconductor gas sensors after their exposure to nonanal as large-molecular-weight volatile organic compounds. The sensors were characterized by their response and temperature-programmed reaction (TPRe), and by transmission electron microscopy (TEM) observation. Sensors pretreated by sufficient aging showed good response but poor resistance recovery with nonanal, whereas good resistance recovery was observed with isoprene. The TPRe analysis revealed that aldehyde gas molecules were oxidized to carboxylic acids on the sensors at the sensor working temperature. In sufficiently aged Pt, Pd, and Au/SnO2 sensors, the loaded Pt, Pd, and Au catalysts were observed to aggregate by TEM. From these results, we suggest different dispersion states of the loaded Pt, Pd, and Au noble metal particles, the mechanism of oxidation and adsorption of nonanal molecules on SnO2 grain surface, and their relationship to the recovery time after exposure to nonanal.
Corresponding author: Toshio ItohCite this article Toshio Itoh, Daiheon Lee, Tomoyo Goto, Takafumi Akamatsu, Noriya Izu, Woosuck Shin, and Toshihiro Kasuga, Analysis of Recovery Time of Pt-, Pd-, and Au-Loaded SnO2 Sensor Material with Nonanal as Large-Molecular-Weight Volatile Organic Compounds, Sens. Mater., Vol. 28, No. 11, 2016, p. 1165-1178. |