Robust reactive oxygen species production in interfacial reaction between organic acids and biochar: The combined effect of electron acceptance and electron conduction

Kecheng Zhu; Sirui Ma; Na Chen; Yunchao Dai; Tiecheng Wang; Xuetao Guo; Hanzhong Jia

doi:10.1016/j.jhazmat.2023.132960

Robust reactive oxygen species production in interfacial reaction between organic acids and biochar: The combined effect of electron acceptance and electron conduction

J Hazard Mater. 2024 Feb 15:464:132960. doi: 10.1016/j.jhazmat.2023.132960. Epub 2023 Nov 10.

Authors

Kecheng Zhu¹, Sirui Ma¹, Na Chen¹, Yunchao Dai¹, Tiecheng Wang¹, Xuetao Guo¹, Hanzhong Jia²

Affiliations

¹ Key Laboratory of Low-carbon Green Agriculture in Northwestern China, Ministry of Agriculture and Rural Affairs, College of Natural Resources and Environment, Northwest A & F University, Yangling 712100, China.
² Key Laboratory of Low-carbon Green Agriculture in Northwestern China, Ministry of Agriculture and Rural Affairs, College of Natural Resources and Environment, Northwest A & F University, Yangling 712100, China. Electronic address: jiahz@nwafu.edu.cn.

PMID: 37976848
DOI: 10.1016/j.jhazmat.2023.132960

Abstract

Interfacial electron transport and reactive oxygen species (ROS) generation in the redox action between biochar (BC) and low-molecular-weight organic acids (LMWOAs) have been overlooked during the utilization of BC in soil amelioration/remediation. Herein, BC and N-doped BC (NBC) with various physicochemical properties were prepared at pyrolysis temperatures of 350, 550 and 750 °C (namely BC/NBC350, 550 and 750) and their interactions with LMWOAs were systematically investigated. Results of ROS quenching and electrochemical cell experiments revealed that BC/NBC could strongly interact with LMWOAs, especially ascorbic acid (AA), and acted as an electron shuttle to mediate one electron transfer from AA to oxygen to generate O₂^•-, followed by the robust generation of H₂O₂ and •OH. Interestingly, the generation rates of •OH and H₂O₂ in the NBC-AA system were significantly higher than that in the BC-AA system, of which the NBC550-AA system exhibited the best performance, enabling its superior ability in bisphenol A degradation. Different from conventional wisdom, the electron shuttle capacity depended on a combined aromatization degree and electron-accepting capacity of BC/NBC. These findings complement the interfacial electron transfer mechanism during the natural BC-LMWOAs interaction and provide new inspiration for the development of green and efficient organic pollutant removal technologies.

Keywords: Electron shuttle; Low-molecular-weight organic acids; N-doped biochar; Organic pollutant removal; Reactive oxygen species.