NO2 sensing properties of macroporous In2O3-based powders fabricated by utilizing ultrasonic spray pyrolysis employing polymethylmethacrylate microspheres as a template

作者：Hyodo Takeo^*; Inoue Hanako; Motomura Hitomi; Matsuo Katsuhide; Hashishin Takeshi; Tamaki Jun; Shimizu Yasuhiro; Egashira Makoto

来源：Sensors and Actuators B: Chemical , 2010, 151(1): 265-273.

DOI：10.1016/j.snb.2010.09.002

• Gas sensor
• Indium oxide
• Ultrasonic spray pyrolysis
• Polymethylmethacrylate
• Macropores

Macroporous (mp-) In2O3-based microspheres as a NO2 sensing material were prepared by the pyrolysis of atomized In(NO3)(3) aqueous solutions containing polymethylmethacrylate (PMMA) microspheres (150 nm in diameter) as a template. Well-developed spherical macropores (less than 100 nm in diameter) reflecting the morphology of the PMMA microsphere templates could be formed in the In2O3-based microspheres. The introduction of macropores into In2O3-based microspheres was very effective in improving the NO2 response of their thick films fabricated on an alumina substrate equipped with inter-digitated Pt electrodes (gap size: ca. 200 mu m) by screen-printing. In addition, the addition of a little amount of SnO2 to the mp-In2O3 microspheres not only lowered the resistance in air but also improved the NO2 response. NO2 sensing properties of non-stacked microspheres of the mp-In2O3 mixed with SnO2 were also investigated by utilizing nano-gap Au electrodes (gap size: ca. 200 nm). The non-stacked microspheres showed fast response and recovery speeds to NO2, because of better diffusion capability of NO2.

• 出版日期2010-11-26