A New Strategy for Humidity Independent Oxide Chemiresistors: Dynamic Self-Refreshing of In2O3Sensing Surface Assisted by Layer-by-Layer Coated CeO2Nanoclusters

Ji Wook Yoon, Jun Sik Kim, Tae Hyung Kim, Young Jun Hong, Yun Chan Kang, Jong Heun Lee

Research output: Contribution to journalArticlepeer-review

78 Citations (Scopus)

Abstract

The humidity dependence of the gas sensing characteristics of metal oxide semiconductors has been one of the greatest obstacles for gas sensor applications during the last five decades because ambient humidity dynamically changes with the environmental conditions. Herein, a new and novel strategy is reported to eliminate the humidity dependence of the gas sensing characteristics of oxide chemiresistors via dynamic self-refreshing of the sensing surface affected by water vapor chemisorption. The sensor resistance and gas response of pure In2O3hollow spheres significantly change and deteriorate in humid atmospheres. In contrast, the humidity dependence becomes negligible when an optimal concentration of CeO2nanoclusters is uniformly loaded onto In2O3hollow spheres via layer-by-layer (LBL) assembly. Moreover, In2O3sensors LBL-coated with CeO2nanoclusters show fast response/recovery, low detection limit (500 ppb), and high selectivity to acetone even in highly humid conditions (relative humidity 80%). The mechanism underlying the dynamic refreshing of the In2O3sensing surfaces regardless of humidity variation is investigated in relation to the role of CeO2and the chemical interaction among CeO2, In2O3, and water vapor. This strategy can be widely used to design high performance gas sensors including disease diagnosis via breath analysis and pollutant monitoring.

Original languageEnglish
Pages (from-to)4229-4240
Number of pages12
JournalSmall
DOIs
Publication statusPublished - 2016 Aug 17

Keywords

  • CeO-InO
  • humidity dependence
  • layer-by-layer assemblies
  • regenerative surfaces
  • semiconductor gas sensors

ASJC Scopus subject areas

  • Biotechnology
  • Biomaterials
  • Engineering (miscellaneous)

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