Lower coordination Co3O4 mesoporous hierarchical microspheres for comprehensive sensitization of triethylamine vapor sensor

Dehao Kong; Jiayin Han; Yubing Gao; Yuan Gao; Weirong Zhou; Guannan Liu; Geyu Lu

doi:10.1016/j.jhazmat.2022.128469

Lower coordination Co₃O₄ mesoporous hierarchical microspheres for comprehensive sensitization of triethylamine vapor sensor

J Hazard Mater. 2022 May 15:430:128469. doi: 10.1016/j.jhazmat.2022.128469. Epub 2022 Feb 10.

Authors

Dehao Kong¹, Jiayin Han¹, Yubing Gao¹, Yuan Gao², Weirong Zhou¹, Guannan Liu¹, Geyu Lu³

Affiliations

¹ State Key Laboratory on Integrated Optoelectronics, Key Laboratory of Gas Sensors, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, Jilin 130012, China.
² State Key Laboratory on Integrated Optoelectronics, Key Laboratory of Gas Sensors, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, Jilin 130012, China. Electronic address: gaoyuan@jlu.edu.cn.
³ State Key Laboratory on Integrated Optoelectronics, Key Laboratory of Gas Sensors, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, Jilin 130012, China. Electronic address: lugy@jlu.edu.cn.

PMID: 35739661
DOI: 10.1016/j.jhazmat.2022.128469

Abstract

Monitoring and detecting triethylamine (TEA) vapor are essential in the organic synthesis industry. Two-dimensional Co₃O₄ nanosheets with large surface areas and multiple active sites are ideal for fabricating chemiresistive gas sensors. However, the face-to-face stacking owing to the high surface energy of nanosheets, would cover up the active sites, obstruct gas diffusion, raise contact resistance, which all hinder its utilization for TEA detection. Herein, the Co₃O₄ mesoporous nanosheets were assembled into hierarchical microspheres by adding the structure-directing agent PVP K30 and combined with a proper annealing temperature, which optimized their grain size, specific surface area, pores structure, oxygen vacancies, and the atomic ratio of Co²⁺ to Co³⁺. And these ultimately improved the detection capability of TEA. The sensor based on Co₃O₄ sphere-300 exhibits the highest sensor response of 34.1-100 ppm TEA and a low detection limit (0.5 ppm) at a low working temperature of 150 °C. The promising properties are mainly due to the combination of several advantages that facilitate simultaneous chemical and electronic sensitization. This work prepared a high-performance TEA gas sensor and verified the improvement of comprehensive sensitization on the gas-sensing performance of two-dimensional metal oxide semiconductors.

Keywords: Comprehensive sensitization; Low coordination cobalt atoms; Low limit of detection; TEA sensor; Three-dimensional assembly.