Co3O4-SnO2 Hollow Heteronanostructures: Facile Control of Gas Selectivity by Compositional Tuning of Sensing Materials via Galvanic Replacement

Hyun Mook Jeong, Jae Hyeok Kim, Seong Yong Jeong, Chang Hoon Kwak, Jong Heun Lee

Research output: Contribution to journalArticlepeer-review

106 Citations (Scopus)

Abstract

Co3O4 hollow spheres prepared by ultrasonic spray pyrolysis were converted into Co3O4-SnO2 core-shell hollow spheres by galvanic replacement with subsequent calcination at 450 °C for 2 h for gas sensor applications. Gas selectivity of the obtained spheres can be controlled by varying the amount of SnO2 shells (14.6, 24.3, and 43.3 at. %) and sensor temperatures. Co3O4 sensors possess an ability to selectively detect ethanol at 275 °C. When the amount of SnO2 shells was increased to 14.6 and 24.3 at. %, highly selective detection of xylene and methylbenzenes (xylene + toluene) was achieved at 275 and 300 °C, respectively. Good selectivity of Co3O4 hollow spheres to ethanol can be explained by a catalytic activity of Co3O4; whereas high selectivity of Co3O4-SnO2 core-shell hollow spheres to methylbenzenes is attributed to a synergistic effect of catalytic SnO2 and Co3O4 and promotion of gas sensing reactions by a pore-size control of microreactors. (Figure Presented).

Original languageEnglish
Pages (from-to)7877-7883
Number of pages7
JournalACS Applied Materials and Interfaces
Volume8
Issue number12
DOIs
Publication statusPublished - 2016 Mar 30

Keywords

  • CoO
  • galvanic replacement
  • gas sensor
  • heterostructure
  • methylbenzene
  • SnO

ASJC Scopus subject areas

  • Materials Science(all)

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