P-p Heterojunction of Nickel Oxide-Decorated Cobalt Oxide Nanorods for Enhanced Sensitivity and Selectivity toward Volatile Organic Compounds

Jun Min Suh, Woonbae Sohn, Young Seok Shim, Jang Sik Choi, Young Geun Song, Taemin L. Kim, Jong Myeong Jeon, Ki Chang Kwon, Kyung Soon Choi, Chong-Yun Kang, Hyung Gi Byun, Ho Won Jang

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

The utilization of p-p isotype heterojunctions is an effective strategy to enhance the gas sensing properties of metal-oxide semiconductors, but most previous studies focused on p-n heterojunctions owing to their simple mechanism of formation of depletion layers. However, a proper choice of isotype semiconductors with appropriate energy bands can also contribute to the enhancement of the gas sensing performance. Herein, we report nickel oxide (NiO)-decorated cobalt oxide (Co3O4) nanorods (NRs) fabricated using the multiple-step glancing angle deposition method. The effective decoration of NiO on the entire surface of Co3O4 NRs enabled the formation of numerous p-p heterojunctions, and they exhibited a 16.78 times higher gas response to 50 ppm of C6H6 at 350 °C compared to that of bare Co3O4 NRs with the calculated detection limit of approximately 13.91 ppb. Apart from the p-p heterojunctions, increased active sites owing to the changes in the orientation of the exposed lattice surface and the catalytic effects of NiO also contributed to the enhanced gas sensing properties. The advantages of p-p heterojunctions for gas sensing applications demonstrated in this work will provide a new perspective of heterostructured metal-oxide nanostructures for sensitive and selective gas sensing.

Original languageEnglish
Pages (from-to)1050-1058
Number of pages9
JournalACS Applied Materials and Interfaces
Volume10
Issue number1
DOIs
Publication statusPublished - 2018 Jan 10
Externally publishedYes

Keywords

  • benzene
  • cobalt oxide
  • gas sensor
  • glancing angle deposition
  • nickel oxide

ASJC Scopus subject areas

  • Materials Science(all)

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  • Cite this

    Suh, J. M., Sohn, W., Shim, Y. S., Choi, J. S., Song, Y. G., Kim, T. L., Jeon, J. M., Kwon, K. C., Choi, K. S., Kang, C-Y., Byun, H. G., & Jang, H. W. (2018). P-p Heterojunction of Nickel Oxide-Decorated Cobalt Oxide Nanorods for Enhanced Sensitivity and Selectivity toward Volatile Organic Compounds. ACS Applied Materials and Interfaces, 10(1), 1050-1058. https://doi.org/10.1021/acsami.7b14545