Co-doped branched ZnO nanowires for ultraselective and sensitive detection of xylene

Hyung Sik Woo, Chang Hoon Kwak, Jaiho Chung, Jong Heun Lee

Research output: Contribution to journalArticle

66 Citations (Scopus)

Abstract

Co-doped branched ZnO nanowires were prepared by multistep vapor-phase reactions for the ultraselective and sensitive detection of p-xylene. Highly crystalline ZnO NWs were transformed into CoO NWs by thermal evaporation of CoCl2 powder at 700 °C. The Co-doped ZnO branches were grown subsequently by thermal evaporation of Zn metal powder at 500 °C using CoO NWs as catalyst. The response (resistance ratio) of the Co-doped branched ZnO NW network sensor to 5 ppm p-xylene at 400 °C was 19.55, which was significantly higher than those to 5 ppm toluene, C2H5OH, and other interference gases. The sensitive and selective detection of p-xylene, particularly distinguishing among benzene, toluene, and xylene with lower cross-responses to C2H5OH, can be attributed to the tuned catalytic activity of Co components, which induces preferential dissociation of p-xylene into more active species, as well as the increase of chemiresistive variation due to the abundant formation of Schottky barriers between the branches.

Original languageEnglish
Pages (from-to)22553-22560
Number of pages8
JournalACS Applied Materials and Interfaces
Volume6
Issue number24
DOIs
Publication statusPublished - 2014 Jan 1

ASJC Scopus subject areas

  • Materials Science(all)

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