Dual Functional Sensing Mechanism in SnO2–ZnO Core–Shell Nanowires

We report a dual functional sensing mechanism for ultrasensitive chemoresistive sensors based on SnO2–ZnO core–shell nanowires (C–S NWs) for detection of trace amounts of reducing gases. C–S NWs were synthesized by a two-step process, in which core SnO2 nanowires were first prepared by vapor–liquid–...

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Bibliographic Details
Published in:ACS applied materials & interfaces 2014-06, Vol.6 (11), p.8281-8287
Main Authors: Choi, Sun-Woo, Katoch, Akash, Sun, Gun-Joo, Kim, Jae-Hun, Kim, Soo-Hyun, Kim, Sang Sub
Format: Article
Language:English
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Summary:We report a dual functional sensing mechanism for ultrasensitive chemoresistive sensors based on SnO2–ZnO core–shell nanowires (C–S NWs) for detection of trace amounts of reducing gases. C–S NWs were synthesized by a two-step process, in which core SnO2 nanowires were first prepared by vapor–liquid–solid growth and ZnO shell layers were subsequently deposited by atomic layer deposition. The radial modulation of the electron-depleted shell layer was accomplished by controlling its thickness. The sensing capabilities of C–S NWs were investigated in terms of CO, which is a typical reducing gas. At an optimized shell thickness, C–S NWs showed the best CO sensing ability, which was quite superior to that of pure SnO2 nanowires without a shell. The dual functional sensing mechanism is proposed as the sensing mechanism in these nanowires and is based on the combination of the radial modulation effect of the electron-depleted shell and the electric field smearing effect.
ISSN:1944-8244
1944-8252
DOI:10.1021/am501107c