Highly sensitive and selective trimethylamine sensor using one-dimensional ZnO-Cr 2O 3 hetero-nanostructures

Hyung Sik Woo, Chan Woong Na, Il Doo Kim, Jong Heun Lee

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Abstract

Highly selective and sensitive detection of trimethylamine (TMA) was achieved by the decoration of discrete p-type Cr 2O 3 nanoparticles on n-type ZnO nanowire (NW) networks. Semielliptical Cr 2O 3 nanoparticles with lateral widths of 38nm were deposited on ZnO NWs by the thermal evaporation of CrCl 2 at 630°C, while a continuous Cr 2O 3 shell layer with a thickness of 3040nm was uniformly coated on ZnO NWs at 670°C. The response (R a/R g: R a, resistance in air; R g, resistance in gas) to 5ppm TMA of Cr 2O 3-decorated ZnO NWs was 17.8 at 400°C, which was 2.4 times higher than that to 5ppm C 2H 5OH and 4.38.4 times higher than those to 5ppm p-xylene, NH 3, benzene, C 3H 8, toluene, CO, and H 2. In contrast, both pristine ZnO and ZnO (core)Cr 2O 3 (shell) nanocables (NCs) showed comparable responses to the different gases. The highly selective and sensitive detection of TMA that was achieved by the deposition of semielliptical Cr 2O 3 nanoparticles on ZnO NW networks was explained by the catalytic effect of Cr 2O 3 and the extension of the electron depletion layer via the formation of pn junctions.

Original languageEnglish
Article number245501
JournalNanotechnology
Volume23
Issue number24
DOIs
Publication statusPublished - 2012 Jun 22

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ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Electrical and Electronic Engineering
  • Mechanical Engineering
  • Mechanics of Materials
  • Materials Science(all)

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