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 language | English |
---|---|
Pages (from-to) | 1050-1058 |
Number of pages | 9 |
Journal | ACS Applied Materials and Interfaces |
Volume | 10 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2018 Jan 10 |
Bibliographical note
Funding Information:This work was financially supported by the Basic Science Research Program (2017R1A2B3009135), the Future Material Discovery Program (2016M3D1A1027666), and the Nano Material Technology Development Program (2016M3A7B4910) through the National Research Foundation of Korea (NRF). J.M.S. acknowledges the Global Ph.D. Fellowship Program through the National Research Foundation of Korea funded by the Ministry of Education (2015H1A2A1033701).
Publisher Copyright:
© 2017 American Chemical Society.
Keywords
- benzene
- cobalt oxide
- gas sensor
- glancing angle deposition
- nickel oxide
ASJC Scopus subject areas
- General Materials Science