Potential-induced sonoelectrochemical graphene nanosheets with vacancies as hydrogen peroxide reduction catalysts and sensors

Tzu-Pei Wang; Chien-Liang Lee; Chia-Hung Kuo; Wen-Cheng Kuo

doi:10.1016/j.ultsonch.2020.105444

Potential-induced sonoelectrochemical graphene nanosheets with vacancies as hydrogen peroxide reduction catalysts and sensors

Ultrason Sonochem. 2021 Apr:72:105444. doi: 10.1016/j.ultsonch.2020.105444. Epub 2020 Dec 24.

Authors

Tzu-Pei Wang¹, Chien-Liang Lee², Chia-Hung Kuo³, Wen-Cheng Kuo⁴

Affiliations

¹ Department of Chemical and Materials Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 807, Taiwan.
² Department of Chemical and Materials Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 807, Taiwan. Electronic address: cl_lee@nkust.edu.tw.
³ Department of Seafood Science, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan.
⁴ Department of Mechatronics Engineering, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan.

Abstract

Defective graphene nanosheets (dGN_4V) with 5-9, 5-8-5, and point defects were synthesised by a sonoelectrochemical method, where a potential of 4 V (vs. Ag/AgCl) was applied to drive the rapid intercalation of phosphate ions between the layers of the graphite foil as a working electrode. In addition to these vacancies, double vacancy defects were also created when the applied potential was increased to 8 V (dGN_8V). The defect density of dGN_8V (2406 μm^-2) was higher than that of dGN_4V (1786 μm^-2). Additionally, dGN_8V and dGN_4V were applied as catalysts for the hydrogen peroxide reduction reaction (HPRR). The mass activity of dGN_8V (1.31 × 10^-2 mA·μg^-1) was greater than that of dGN_4V (1.17 × 10^-2 mA·μg^-1) because of its high electrochemical surface area (ECSA, 1250.89 m²·g^-1) and defect density (N_D, 2406 μm^-2), leading to low charge transfer resistance on the electrocatalytic interface. The ECSA and N_D of dGN_4V were 502.7 m²·g^-1 and 1786 μm^-2, respectively. Apart from its remarkable HPRR activity, the cost-effective dGN_8V catalyst also showed potential as an amperometric sensor for the determination of H₂O₂.

Keywords: Amperometric sensor; Defect effect; Reaction kinetics; Specific activity; Ultrasound.