Pure and Pr-doped Ce4W9O33with superior hydroxyl scavenging ability: Humidity-independent oxide chemiresistors

Jun Sik Kim, Ki Beom Kim, Hua Yao Li, Chan Woong Na, Kyeorei Lim, Young Kook Moon, Ji Won Yoon, Jong Heun Lee

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


Water poisoning has been a long-standing problem in oxide semiconductor gas sensors. Herein, for the first time, we report that pure and Pr-doped Ce4W9O33 provide humidity-independent gas sensing characteristics. Ce4W9O33 and Pr-doped Ce4W9O33 powders with a porous structure have been successfully prepared by ultrasonic spray pyrolysis and subsequent annealing at low temperature (600 °C). Interestingly, these p-type oxide semiconductors exhibited nearly the same gas sensing characteristics at 300 °C regardless of humidity variation, whereas pure WO3 showed a significant decrease of sensor resistance and gas response when the atmosphere is changed from dry to relative humidity 80%. Furthermore, Ce4W9O33-based sensors showed highly selective and sensitive detection of ppm-level trimethylamine (TMA). Moisture-endurant gas sensing characteristics were discussed in relation to surface regeneration through the hydroxyl scavenging reaction assisted by abundant Ln3+ (Ln = Ce, Pr) in (Ce1-xPrx)4W9O33 (x = 0-0.3) and TMA selectivity was explained by the acid-base interaction between the analyte gas and sensing material. Phase-pure ternary or quaternary oxides with a decreased oxidation state of lanthanide components provide a new and general strategy to design humidity-independent gas sensors with new functionality.

Original languageEnglish
Pages (from-to)16359-16369
Number of pages11
JournalJournal of Materials Chemistry A
Issue number30
Publication statusPublished - 2021 Aug 14

ASJC Scopus subject areas

  • Chemistry(all)
  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)


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