Boosting Electrical Response toward Trace Volatile Organic Compounds Molecules via Pulsed Temperature Modulation of Pt Anchored WO3 Chemiresistor

• DOI: 10.1002/smtd.202200728
• Publication Date: 2022-08-26T18:50:35Z
• Authors: Tiantian Dai; Zhi Yan; Meng Li; Yulei Han; Zanhong Deng; Shimao Wang; Ruyang Wang; Xiaohong Xu; Lei Shi; Wei Tong; Jun Bao; Zhenhua Qiao; Liang Li; Gang Meng
• Keywords: Chemiresistor; Microheater

Insufficient limit of detection (LoD) toward volatile organic compounds (VOCs) hinders the promising applications metal oxide chemiresistors in emerging air quality monitoring and/or breath analysis. There is an inherent limitation widely adopted strategies creating sensitive then operating at optimized temperature via a continuous heating (CH) mode. Herein, strategy combining Pt single atoms anchoring (chemical sensitization) with pulsed modulation (PTM, physical proposed. Apart from generating abundant surface asymmetric oxygen vacancy (Pt-VO -W) active sites high (HT) stage, inward diffusion trace target VOCs across sensing layer low stage (driven by PTM induced concentration gradient), can greatly enhance charge interaction probability between generated species and surrounding VOCs, thus offers novel avenue on addressing bottleneck issue LoD PTM. Triggered HT 300 °C, responses anchored WO3 chemiresistor to 1 ppm trimethylamine (TMA) xylene be drastically boosted 1.9 6541.5 (PTM) 1.5 1001.1 (PTM), respectively. And ultra-low theoretic 0.78 ppt 0.18 (xylene) are successfully achieved,