Activation of O2 by zero-valent zinc assisted with Cu(II) for organics removal: Performance and mechanism

Zhiwei Yang; Yiwen Luo; Jiapeng Yue; Xinyu Wang; Hao Xu; Qian Ye; Yujian Zhang; Xinyi Xing; Qingguo Wang; Jing Zhang

doi:10.1016/j.jhazmat.2021.127506

Activation of O₂ by zero-valent zinc assisted with Cu(II) for organics removal: Performance and mechanism

J Hazard Mater. 2022 Feb 15;424(Pt B):127506. doi: 10.1016/j.jhazmat.2021.127506. Epub 2021 Oct 14.

Authors

Zhiwei Yang¹, Yiwen Luo¹, Jiapeng Yue¹, Xinyu Wang¹, Hao Xu¹, Qian Ye¹, Yujian Zhang¹, Xinyi Xing¹, Qingguo Wang², Jing Zhang³

Affiliations

¹ College of Architecture & Environment, Sichuan University, Chengdu 610065, China.
² College of Architecture & Environment, Sichuan University, Chengdu 610065, China; Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China.
³ College of Architecture & Environment, Sichuan University, Chengdu 610065, China; State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China. Electronic address: zjing428@163.com.

PMID: 34666294
DOI: 10.1016/j.jhazmat.2021.127506

Abstract

This study proposes a method to activate O₂ by accelerating the corrosion process for zero-valent zinc (ZVZ) with the assistance of Cu(II), promoting the consecutive production of reactive oxygen species. The mechanisms for reactive oxygen species generation are clarified with metronidazole (MTZ) as the targeted pollutant. The outcome suggests the association of Cu(Ⅱ) and ZVZ presents an apparent cooperative activity, an enhancement of 85% in MTZ removal is attained for the ZVZ/Cu(Ⅱ) system after 10 min compared to that for ZVZ. Analysis of the mechanisms involved indicates that this improvement is due to the addition of Cu(Ⅱ), which can accelerate the corrosion of ZVZ. In addition, quenching experiments and electron paramagnetic resonance (EPR) technology show that superoxide radicals (·O₂^-) result in rapid MTZ degradation. The primary component that is liable for O₂ activation and a certain amount of H₂O₂ generation is verified to be ZVZ. Moreover, Cu(I) is detected in the ZVZ/Cu(Ⅱ) system, which arises from a direct reduction pathway driven by ZVZ and an indirect reduction pathway driven by active hydrogen atoms.

Keywords: Cu(II)/Cu(I) redox couple; H(2)O(2) generation; O(2) activation; Zero-valent zinc.

Publication types

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

MeSH terms

Copper
Electron Spin Resonance Spectroscopy
Hydrogen Peroxide*
Oxidation-Reduction
Reactive Oxygen Species
Zinc*

Substances

Reactive Oxygen Species
Copper
Hydrogen Peroxide
Zinc