H2S gas sensing performance and mechanisms using CuO-Al2O3 composite films based on both surface acoustic wave and chemiresistor techniques

Research output: Contribution to journalArticle


  • Yongliang Tang
  • Wu Wei
  • Bangji Wang
  • Xucheng Dai
  • wanfang Xie
  • Youwei Yang
  • Ruijie Zhang
  • Xin Shi
  • Hao Zhu
  • Jia Luo
  • Yuanjun Guo
  • Xiaotao Zu
  • Richard Fu


Original languageEnglish
Article number128742
JournalSensors and Actuators B: Chemical
Early online date14 Aug 2020
Publication statusE-pub ahead of print - 14 Aug 2020
Publication type

Research output: Contribution to journalArticle


Surface acoustic wave and chemiresistor based gas sensors integrated with a sensing layer of sol-gel CuO-Al2O3 composite film were fabricated and their performance and mechanisms for H2S sensing were characterized and compared. In the composite film, CuO nanoparticles provide active sites for adsorption and reaction of H2S molecules while Al2O3 nanoparticles help to form a uniform and mesoporous film structure, both of which enhance the sensitivity of the sensors by providing numerous active CuO surfaces. Through the comparative studies, the SAW based H2S sensor operated at room temperature showed a lower detection limit, higher sensitivity, better linearity and good selectivity to H2S gas with its concentration ranging from 5 ppb to 100 ppm, compared with those of the chemiresistor sensor, which are mainly attributed to the effective mass sensing properties of the SAW sensor, because a minor change in the mass of the film caused by adsorbed H2S molecules would lead to a significant and monotonous change of the resonant frequency of the SAW devices.