P2NG.8 - Formaldehyde Sensor Based on Flame-made AgOx-doped SnO2 Nanoparticulate Sensing Films

Event
17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
Vienna, Austria
Chapter
P-2 - Nanomaterials for Gas Sensing
Author(s)
K. Khamfoo - Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai (Thailand), A. Wisitsoraat, A. Tuantranont, S. Phanichphant, C. Liewhiran - Center of Advanced Materials for Printed Electronics and Sensors, Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai (Thailand)
Pages
859 - 860
DOI
10.5162/IMCS2018/P2NG.8
ISBN
978-3-9816876-9-9
Price
free

Abstract

Formaldehyde (HCHO) is one kind of the most volatile organic compounds (VOCs) that was widely used in household materials associated with many health risk factors and is identified as a major cause of sick building syndrome (SBS) [1, 2]. It is thus important to develop sensitive gas sensors capable of formaldehyde dection below its threshold limit value (TLVs) for health safety. In this work, flame-made 0-1 wt% AgOx-doped SnO2 nanoparticles were developed and characterized for detection of HCHO. The structural properties of as-prepared materials and their fabricated sensors were characterized by X-ray diffraction, Energy-dispersive X-ray spectroscopy, nitrogen adsorption, and electron microscopy. The results indicated that the AgOx-doped SnO2 nanoparticles ( 20 nm) had spheriodal morphology with highly crystalline tetragonal cassiterite SnO2 structure and AgOx may form a solid solution with SnO2 matrix. For gas sensing test, the gas sensing properties of the pure SnO2 and AgOx-doped SnO2 sensing film were systematically tested under exposure towards 50-200 ppm HCHO with different operating temperatures ranging from 150-400°C in dry air. From the sensing data, AgOx doping with an optimal Ag content of 0.2 wt% led to significant enhancement of HCHO response by more than one order of magnitude compared with undoped one. In particular, 0.2 wt% AgOx-doped SnO2 sensing film exhibited a high response of ~500 to 2000 ppm HCHO at 350°C. Therefore, the flame-spray-made 0.2 wt% AgOx-doped SnO2 sensor is one of the most promising candidate for sensitive HCHO detector and may be useful in environmental and SBS applications.

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