Ionic liquid combined with NiCo2O4/rGO enhances electrochemical oxygen sensing

Lin Yu; Jingyuan Liu; Wenyan Yin; Jing Yu; Rongrong Chen; Dalei Song; Qi Liu; Rumin Li; Jun Wang

doi:10.1016/j.talanta.2019.120515

Ionic liquid combined with NiCo₂O₄/rGO enhances electrochemical oxygen sensing

Talanta. 2020 Mar 1:209:120515. doi: 10.1016/j.talanta.2019.120515. Epub 2019 Oct 31.

Authors

Lin Yu¹, Jingyuan Liu², Wenyan Yin¹, Jing Yu¹, Rongrong Chen³, Dalei Song¹, Qi Liu⁴, Rumin Li⁵, Jun Wang⁶

Affiliations

¹ Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin, 150001, PR China; College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, PR China.
² Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin, 150001, PR China; College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, PR China. Electronic address: liujingyuan1004@hrbeu.edu.cn.
³ Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin, 150001, PR China; College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, PR China; Institute of Advanced Marine Materials, Harbin Engineering University, 150001, PR China.
⁴ Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin, 150001, PR China; College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, PR China; Harbin Engineering University Capital Management Co. Ltd, Harbin, 150001, PR China. Electronic address: qiliu@hrbeu.edu.cn.
⁵ Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin, 150001, PR China; College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, PR China; Harbin Engineering University Capital Management Co. Ltd, Harbin, 150001, PR China.
⁶ Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin, 150001, PR China; College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, PR China; Harbin Engineering University Capital Management Co. Ltd, Harbin, 150001, PR China; Institute of Advanced Marine Materials, Harbin Engineering University, 150001, PR China.

PMID: 31892070
DOI: 10.1016/j.talanta.2019.120515

Abstract

Ionic liquids are promising electrolytes for electrochemical gas sensors that have unique physicochemical properties such as negligible vapor pressure and high thermal stability. The modification of ionic liquid (IL) by combining metal oxide with reduced graphene oxide (rGO) is an effective method to improve its gas-sensing properties. In this study, the mesoporous structure of NiCo₂O₄/rGO is synthesized by simple one-step method, and the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF₆]) is mixed with it to form the composite material NiCo₂O₄/rGO/[BMIM][PF₆]. Electrochemical test results indicate that the three electrolytes exhibit response current and long-term stability in the oxygen environment. The oxygen sensor based on NiCo₂O₄/rGO/[BMIM][PF₆] significantly improves the response current and working stability of pure ionic liquid. The sensitivity of the sensor is 0.1087 μA/[%O₂], and the linear regression coefficient of the reduction peak current calibration curve is 0.9995. After continuous cyclic voltammetry, the reduction peak current remains at 90% of the initial current value. The interaction of IL and NiCo₂O₄/rGO significantly enhances electrochemical oxygen sensing performance.

Keywords: Ionic liquid; NiCo(2)O(4); Oxygen sensor; Reduced graphene oxide.