Selective H2S gas sensors based on ohmic hetero-interface of Au-functionalized WO3 nanowires

Year: 2022

Authors: Punginsang M., Zappa D., Comini E., Wisitsoraat A., Sberveglieri G., Ponzoni A., Liewhiran C.

Autors Affiliation: Chiang Mai Univ, Dept Phys & Mat Sci, Fac Sci, Chiang Mai 50200, Thailand; Chiang Mai Univ, Ctr Excellence Mat Sci & Technol, Chiang Mai 50200, Thailand; Univ Brescia, Dept Informat Engn, Sensor Lab, Via Valotti 9, I-25133 Brescia, Italy; Natl Sci & Technol Dev Agcy NSTDA, Natl Secur & Dual Use Technol Ctr, Klongluang 12120, Phathum Thani, Thailand; Unit Brescia, Natl Inst Opt, Natl Res Council CNR INO, I-25123 Brescia, Italy.

Abstract: In this present study, the fabricated sensors based on WO3 nanowires sensing films were grown by thermal oxidation method on the alumina substrates in single step and subsequently functionalized with gold nano- particles, an excellent catalyst for gas-sensing reactions, by RF magnetron sputtering with different sputtering time of 2, 5, 10 and 15 s. Structural characterizations of sensing films by electron microscopy and X-ray analysis revealed that 5–15 nm Au nanoparticles with a single metallic state decorated the highly crystalline 20–30 nm WO3 nanowires with a monoclinic structure. The effect of Au sputtering time on gas sensing properties of WO3 sensors was systematically tested towards H2S, CO, NO2 and acetone, with different working temperatures ranging from 250 to 400 ◦C in dry air and humidity effects. It was found that an optimal Au sputtering time of 10 s led to significant enhancement of H2S-sensing performances compared with other tested gases. Particularly, the optimal Au-functionalized WO3 sensing film exhibited the highest response of 219 to 5 ppm H2S with the detection limit of 0.17 ppb at the optimal working temperature of 350 degC and a relative humidity of 50% (@20 degC). Therefore, the Au-functionalized WO3 nanowires are highly potential for selective H2S detection.

Journal/Review: APPLIED SURFACE SCIENCE

Volume: 571      Pages from: 151262-1  to: 151262-11

More Information: The authors gratefully acknowledge the financial support from Erasmus Mundus LEADER: Links in Europe and Asia for engineering eDucation, Enterprise and Research scholarship 2016/2017, the MidCareer Research Grant 2020 (This project is funded by National Research Council of Thailand (NRCT): NRCT5-RSA63004-04), Global Partnership (This research was financially supported by the Program Management Unit for Human Resources & Institutional Development, Research and Innovation, Office of National Higher Education Science Research and Innovation Policy Council (NXPO) [Grant Number B16F640001]). We wish to thank Center of Excellence (CoE) in Materials Science and Technology, Chiang Mai University for financial support under the administration of Materials Science Research Center, Faculty of Science, Chiang Mai University, the National Research University (NRU) Project under the Office of the Higher Education Commission (CHE), Ministry of Education, Thailand. Additionally, the authors gratefully acknowledge the Thailand Research Fund for TRF Research Team Promotion Grant (RTA6180004) and National Science and Technology Development Agency (NSTDA). The special thanks should be given to Chemical Sensor Laboratory (CSL), Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, the National Electronics and Computer Technology Center (NECTEC), Pathumthani, Thailand, and Sensor Laboratory, Department of Information Engineering, University of Brescia, Italy for the material preparations and sensor facilities.
KeyWords: WO3; Nanowires; Thermal oxidation; Gold; Gas sensors
DOI: 10.1016/j.apsusc.2021.151262

Citations: 51
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