Enhanced Free-Radical Generation on MoS2 /Pt by Light and Water Vapor Co-Activation for Selective CO Detection with High Sensitivity

Yi Xia; Shenghui Guo; Li Yang; Sufang He; Liexing Zhou; Mingjun Wang; Jiyun Gao; Ming Hou; Jing Wang; Sridhar Komarneni

doi:10.1002/adma.202303523

Enhanced Free-Radical Generation on MoS₂ /Pt by Light and Water Vapor Co-Activation for Selective CO Detection with High Sensitivity

Adv Mater. 2023 Jul;35(30):e2303523. doi: 10.1002/adma.202303523. Epub 2023 Jun 19.

Authors

Yi Xia^{1

2}, Shenghui Guo², Li Yang², Sufang He¹, Liexing Zhou¹, Mingjun Wang¹, Jiyun Gao², Ming Hou², Jing Wang³, Sridhar Komarneni⁴

Affiliations

¹ Research Center for Analysis and Measurement, Kunming University of Science and Technology, Analytic & Testing Research Center of Yunnan, Kunming, 650093, China.
² The Key Laboratory of Unconventional Metallurgy, Ministry of Education, Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, 650093, China.
³ School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China.
⁴ Department of Ecosystem Science and Management and Materials Research Institute, 204 Energy and the Environment Laboratory, The Pennsylvania State University, University Park, PA, 16802, USA.

PMID: 37269248
DOI: 10.1002/adma.202303523

Abstract

Semiconductor-based gas sensors hold great promise for effective carbon monoxide (CO) detection. However, boosting sensor response and selectivity remains a key priority in moist conditions. In this study, a composite material, Pt quantum dots decorated MoS₂ nanosheets (MoS₂ /Pt), is developed as a highly sensitive material for CO detection when facilitated with visible light. The MoS₂ /Pt sensor shows a significantly improved response (87.4%) with impressive response/recovery kinetics (20 s/17 s), long-term stability (60 days), and good selectivity to CO at high humidity (≈60%). It is confirmed both experimentally and theoretically that the MoS₂ /Pt surface lowers the activation energy to convert CO to CO₂ via the free radicals induced by the synergy of photochemical effects and water vapor. As a result, the MoS₂ /Pt surface promotes both CO response and selectivity, providing fundamental clues to improve room-temperature semiconductor-based sensors for gas detection under extreme conditions.

Keywords: MoS2/Pt; free radicals; light; selective CO sensing; water vapor.

Abstract

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