Synthesis and gas-sensing properties of nano- and meso-porous MoO3-doped SnO2

SENSORS AND ACTUATORS B-CHEMICAL

卷:147

Article

Firooz, Azam Anaraki^1,2  Hyodo, Takeo¹  Mahjoub, Ali Reza²  Khodadadi, Abbas Ali³  Shimizu, Yasuhiro¹ 

[1] Nagasaki Univ, Fac Engn, Dept Mat Sci & Engn, Nagasaki 8528521, Japan

[2] Tarbiat Modares Univ, Dept Chem, Tehran 14115175, Iran

[3] Univ Tehran, Sch Chem Engn, Tehran 111554563, Iran

关键词: SnO2;    Porous structure;    MoO3;    Gas sensor;    Ultrasonic spray-pyrolysis;   

DOI  :  10.1016/j.snb.2010.03.021

来源: Elsevier

【 摘 要 】

Nano- and meso-porous SnO2 powders doped with and without 1-10 wt% MoO3 have been synthesized by an ultrasonic spray-pyrolysis method employing a precursor aqueous solution containing tin (IV) chloride pentahydrate (SnCl4 center dot 5H(2)O), ammonium heptamolybdate and polymethylmethacrylate (PMMA) microspheres as a template, and the effects of MoO3-doping and the addition of PMMA microspheres on the structural, morphological and gas-sensing properties of SnO2 were investigated in this study. It is confirmed that control of the amounts of PMMA microspheres in the precursor solution was effective in realizing well-developed nano- and meso-porous structures of SnO2 by X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy. X-ray photoelectron spectroscopy, and the measurement of specific surface area and pore size distribution using a N-2 adsorption isotherm. Gas-sensing properties of their thick films (about 50 mu m thick), which were fabricated by screen-printing to various gases (NO2, C2H5OH and H-2) were tested in ambient air. The doped thick films showed a high response and selectivity to 5 ppm NO2 gas in the case of 10 wt% MoO3-doping in both nano- and meso-porous structures of SnO2. We observed that the presence of Mo species in SnO2 lattice can improve the sensor response and selectivity towards NO2 gas. The effect of the MoO3-doping on the sensing characteristics of these films towards NO2 was discussed. (C) 2010 Elsevier B.V. All rights reserved.

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