Gas sensing behavior of p-NiO/n-ZnO composite nanofibers depending on varying p-NiO content: Selectivity and humidity-independence for oxidizing and reducing gas molecules

Changhyun Jin, Myung Sik Choi, Kyu Hyoung Lee, Sun Woo Choi

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In this work, we fabricated gas sensors based on p-type NiO/n-type ZnO composite nanofibers (NFs), which could selectively detect oxidizing and reducing gas molecules. The p-type NiO/n-type ZnO composite NFs with both hetero- and homojunctions were successfully synthesized, and their sensing performances for oxidizing and reducing gases were systematically investigated with different composition ratios of p-type NiO and n-type ZnO. Interestingly, for oxidizing and reducing gases, the 0.5NiO-0.5ZnO NFs (nominal composition) exhibited an excellent gas response to oxidizing gases such as NO2 and SO2, whereas the 0.8NiO-0.2ZnO NFs (nominal composition) showed good selectivity for reducing gases such as C3H6O, C2H5OH, and NH3. In addition, we also examined the NO2 and CO sensing performance under a humid atmosphere to confirm the role of the NiO component, which possesses high affinity for water molecules, in p-type NiO/n-type ZnO composite NFs. We discussed the correlation between variations in composition and sensing performances with respect to gas sensing behavior, selectivity, and humidity effect for oxidizing and reducing gases. The results reveal that we successfully imparted selectivity for oxidizing and reducing gas molecules to the p-type NiO/n-type ZnO composite NFs by adjusting the composition ratio of NiO/ZnO.

Original languageEnglish
Article number130813
JournalSensors and Actuators, B: Chemical
Publication statusPublished - 2021 Dec 15

Bibliographical note

Funding Information:
This research was supported by Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education ( NRF-2017R1D1A3B03036356 and NRF-2019R1A6A1A11055660 ). This study was supported by 2018 Research Grant from Kangwon National University.

Publisher Copyright:
© 2021

All Science Journal Classification (ASJC) codes

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

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