Pure and Pr-doped Ce4W9O33 with superior hydroxyl scavenging ability: humidity-independent oxide chemiresistors. Issue 30 (23rd June 2021)

• Record Type: Journal Article
• Authors: Kim, Jun-Sik; Kim, Ki Beom; Li, Hua-Yao; Na, Chan Woong; Lim, Kyeorei; Moon, Young Kook; Yoon, Ji Won; Lee, Jong-Heun
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 30(2021)
• Page Start: 16359
• Page End: 16369
• Publication Date: 2021-06-23
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1ta02618f
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Highly sensitive, selective and humidity-independent detection of trimethylamine was achieved using p-type semiconducting pure and Pr-doped Ce4 W9 O33 . Abstract : 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 Ce4 W9 O33 provide humidity-independent gas sensing characteristics. Ce4 W9 O33 and Pr-doped Ce4 W9 O33 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, Ce4 W9 O33 -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 Ln 3+ (Ln = Ce, Pr) in (Ce1− x Pr x )4 W9 O33 ( 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.