Journal of Sensor Science and Technology (센서학회지)

The Korean Sensors Society (한국센서학회)
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Fabrication and characteristics of NOx gas sensors using WO3 and In2O3 thick films to monitor air pollution

  • Son, M.W. (Department of Materials Science and Engineering, University of Seoul) ;
  • Choi, J.B. (Department of Materials Science and Engineering, University of Seoul) ;
  • Hwang, H.I. (Convergence Components R&D Division, Korea Electronics Technology Institute) ;
  • Yoo, K.S. (Department of Materials Science and Engineering, University of Seoul)
  • 손명우 (서울시립대학교 대학원) ;
  • 최정범 (서울시립대학교 대학원) ;
  • 황학인 (전자부품연구원 융합부품연구본부) ;
  • 유광수 (서울시립대학교 교무처)
  • Published : 2009.07.31
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Abstract

With the increasing number of automobiles, the problem of air pollution from the exhaust gases of automobiles has become a critical issue. The principal gases that cause air pollution are nitrogen oxide or NO$_x$(NO and NO$_2$), and CO. Because NO$_x$ gases cause acid rain and global warming and produce ozone(O$_3$) that leads to serious metropolitan smog from photochemical reaction, they must be detected and reduced. Mixtures of WO$_3$ and $In_2O_3$(WO$_3$:$In_2O_3$=10:0, 7:3, 5:5, 3:7, and 0:10 in wt.%), which are NO$_x$ gas-sensing materials, were prepared, and thick-film gas sensors that included a heater and a temperature sensor were fabricated. Their sensitivity to NO$_x$ was measured at 250$\sim$400$^{\circ}C$ for NO$_x$ concentrations of 1$\sim$5 ppm. The $In_2O_3$ thick-film sensor showed excellent sensitivity($R_{gas}/R_{air}$=10.22) at 300$^{\circ}C$ to 5-ppm NO. The response time for 70 % saturated sensitivity was about 3 seconds, and the sensors exhibited very fast reactivity to NO$_x$.

Keywords

References

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