Ultrasensitive detection of trimethylamine using Rh-doped SnO2 hollow spheres prepared by ultrasonic spray pyrolysis

Yoon Ho Cho, Xishuang Liang, Yun Chan Kang, Jong Heun Lee

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An ultrasensitive trimethylamine (TMA) sensor was achieved using Rh-doped SnO2 hollow spheres prepared by ultrasonic spray pyrolysis followed by heat treatment at 500 °C, and the effects of Rh doping on TMA sensing characteristics were investigated. The response (resistance ratio) of the Rh-doped SnO2 hollow spheres to 5 ppm TMA at 400°C was 1177.5, which is 33 times higher than that of pure SnO2 hollow spheres. The detection limit of the sensor was as low as 5 ppb. In addition, the Rh-doped SnO2 hollow spheres showed negligible cross-responses to HCHO, benzene, toluene, p-xylene, NH3, CO, H2, and NO2, and a decreased cross-response to C2H5OH, whereas pure SnO2 hollow spheres did not show selective detection of a specific gas. The ultrahigh sensitivity and selective detection to TMA were attributed to the electronic interactions between Rh and SnO2 and the high catalytic activity of Rh to TMA.

Original languageEnglish
Pages (from-to)330-337
Number of pages8
JournalSensors and Actuators, B: Chemical
Issue numberPA
Publication statusPublished - 2014 Jan 1



  • Gas sensor
  • Rh-doped SnO hollow sphere
  • Trimethylamine
  • Ultra-low detection limit
  • Ultrasonic spray pyrolysis

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials
  • Metals and Alloys
  • Surfaces, Coatings and Films
  • Materials Chemistry
  • Instrumentation

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