The development of high performance gas sensors that operate at room temperature has attracted considerable attention. Unfortunately, the conventional mechanism of chemiresistive sensors is restricted at room temperature by insufficient reaction energy with target molecules. Herein, novel strategy for room temperature gas sensors is reported using an ionic-activated sensing mechanism. The investigation reveals that a hydroxide layer is developed by the applied voltages on the SnO2 surface in the presence of humidity, leading to increased electrical conductivity. Surprisingly, the experimental results indicate ideal sensing behavior at room temperature for NO2 detection with sub-parts-per-trillion (132.3 ppt) detection and fast recovery (25.7 s) to 5 ppm NO2 under humid conditions. The ionic-activated sensing mechanism is proposed as a cascade process involving the formation of ionic conduction, reaction with a target gas, and demonstrates the novelty of the approach. It is believed that the results presented will open new pathways as a promising method for room temperature gas sensors.
Bibliographical noteFunding Information:
Y.G.S. and Y.‐S.S. contributed equally to this work. This work was supported by an Institute for Information & Communications Technology Promotion (IITP) grant funded by the Korean government (MSIP; Ministry of Science, ICT & Future Planning; No. 2019‐0‐00725, Development of Non‐contact Dementia Screening and Cognitive Enhancer Content Technology); Korea Institute of Science and Technology (KIST through 2E29400); the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Science and ICT (NRF‐2017M3A7B4049176); the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIT) (No. 2019R1A2B5B01070286).
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
- gas sensors
- ionic conduction
- room temperature
ASJC Scopus subject areas
- Materials Science(all)