Efficient H2O2 generation and spontaneous OH conversion for in-situ phenol degradation on nitrogen-doped graphene: Pyrolysis temperature regulation and catalyst regeneration mechanism

Pei Su; Minghua Zhou; Ge Song; Xuedong Du; Xiaoye Lu

doi:10.1016/j.jhazmat.2020.122681

Efficient H₂O₂ generation and spontaneous OH conversion for in-situ phenol degradation on nitrogen-doped graphene: Pyrolysis temperature regulation and catalyst regeneration mechanism

J Hazard Mater. 2020 Oct 5:397:122681. doi: 10.1016/j.jhazmat.2020.122681. Epub 2020 May 8.

Authors

Pei Su¹, Minghua Zhou², Ge Song¹, Xuedong Du¹, Xiaoye Lu¹

Affiliations

¹ Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China; Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China; Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China; Tianjin Advanced Water Treatment Technology International Joint Research Center, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China.
² Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China; Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China; Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China; Tianjin Advanced Water Treatment Technology International Joint Research Center, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China. Electronic address: zhoumh@nankai.edu.cn.

PMID: 32416381
DOI: 10.1016/j.jhazmat.2020.122681

Abstract

H₂O₂ is a green and valuable chemical that can be electrochemically synthesis from oxygen reduction, offering in-situ application for organic pollutants removal in environmental remediation. However, how to improve activity and further convert into powerful radicals is a still challenge. Herein, we show a facile and general approach to fabricate nitrogen-doped graphene (N-GE) catalyst via pyrolysis temperature regulation. The optimal N-GE at 400 °C exhibited the highest active N content (12.2 wt.%) and H₂O₂ selectivity (85.45 %) and spontaneous OH production (19.42 μM), achieving a high phenol degradation (93.58 %) at 180 min in neutral pH condition. Importantly, a simple catalyst regeneration method and mechanism was disclosed. It is proposed that the conversion of graphite N and pyridinic N in N-GE plays an important role in oxygen reduction reaction (ORR) and OH conversion, while the conversion of pyridinic N-oxide to pyridinic N is critical to catalyst stability and sustainability. This study provides a new insight into structure design of electro-catalyst about stability of nitrogen-doped carbon materials for efficient H₂O₂ generation and cost-effective pollutants removal.

Keywords: Catalyst regeneration mechanism; Nitrogen conversion; Nitrogen-doped graphene; Radical catalytic conversion; Temperature regulation.

Publication types

Research Support, Non-U.S. Gov't