Hydrothermal synthesis of hierarchical CoO/SnO2 nanostructures for ethanol gas sensor

Qingji Wang; Xueying Kou; Chang Liu; Lianjing Zhao; Tingting Lin; Fangmeng Liu; Xueli Yang; Jun Lin; Geyu Lu

doi:10.1016/j.jcis.2017.11.073

Hydrothermal synthesis of hierarchical CoO/SnO₂ nanostructures for ethanol gas sensor

J Colloid Interface Sci. 2018 Mar 1:513:760-766. doi: 10.1016/j.jcis.2017.11.073. Epub 2017 Dec 1.

Authors

Qingji Wang¹, Xueying Kou², Chang Liu², Lianjing Zhao², Tingting Lin³, Fangmeng Liu², Xueli Yang², Jun Lin³, Geyu Lu⁴

Affiliations

¹ College of Instrumentation and Electrical Engineering, Jilin University, Ximinzhu Street, Changchun 130061, China. Electronic address: wangqingji@jlu.edu.cn.
² State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China.
³ College of Instrumentation and Electrical Engineering, Jilin University, Ximinzhu Street, Changchun 130061, China.
⁴ State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China. Electronic address: lugy@jlu.edu.cn.

PMID: 29222975
DOI: 10.1016/j.jcis.2017.11.073

Abstract

In this work, ethanol gas sensor with high performance was fabricated successfully with hierarchical CoO/SnO₂ heterojunction by two-steps hydrothermal method. The response value of CoO/SnO₂ sensor is up to 145 at 250 °C when exposed to 100 ppm ethanol gas, which is much higher than that (13.5) of SnO₂ sensor. These good sensing performances mainly attribute to the formation of the CoO/SnO₂ heterojunction, which makes great variation of resistance in air and ethanol gas. Thus, the combination of n-type SnO₂ and p-type CoO provides an effective strategy to design new ethanol gas sensors. The unique nanostructure also played an important role in detecting ethanol, due to its contribution in facilitating the transport rate of the ethanol gas molecules. Also, we provide a general two-step strategy for designing the heterojunction based on the SnO₂ nanostructure.

Keywords: CoO/SnO(2); Gas sensor; Heterojunction; Hydrothermal.