Enhanced CO sensing characteristics of hierarchical and hollow In2O3 microspheres

Kwon Il Choi, Hae Ryong Kim, Jong Heun Lee

Research output: Contribution to journalArticlepeer-review

131 Citations (Scopus)


Hierarchical and hollow In2O3 microspheres were prepared by a solvothermal self-assembly reaction and their CO sensing characteristics were compared to those of an agglomerated counterpart. Upon exposure to 10-50 ppm CO at 400 °C, the gas responses (Ra/Rg; Ra: resistance in air, Rg: resistance in gas) of the hierarchical and hollow structures were 1.6-2.7 times higher than that of the agglomerated sample. In addition, their 90% responses and recovery speeds were 23 times and 7.7 times higher, respectively. Their significantly improved gas responses and sensing/recovery kinetics were concluded to be related to the nanoporous and well-aligned nanostructures, which allow effective and rapid gas diffusion toward the sensing surfaces.

Original languageEnglish
Pages (from-to)497-503
Number of pages7
JournalSensors and Actuators, B: Chemical
Issue number2
Publication statusPublished - 2009 May 6

Bibliographical note

Funding Information:
This work was supported by KOSEF NRL program grant funded by the Korean government (MEST) (No. R0A-2008-000-20032-0) and by a project, “Technologies development for future home appliance,” funded by Ministry of Knowledge Economy.


  • Gas sensing kinetics
  • Hierarchical nanostructures
  • Hollow spheres
  • InO

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry


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