Nitrogen-doped carbon-coated Cu0 activates molecular oxygen for norfloxacin degradation over a wide pH range

Yanjing Liu; Ruitao Wang; Shuhong Liu; Yunsong Xu; Zhirong Zhang; Ying Song; Zhongping Yao

doi:10.1016/j.jcis.2024.03.189

Nitrogen-doped carbon-coated Cu⁰ activates molecular oxygen for norfloxacin degradation over a wide pH range

J Colloid Interface Sci. 2024 Jul:665:945-957. doi: 10.1016/j.jcis.2024.03.189. Epub 2024 Mar 29.

Authors

Yanjing Liu¹, Ruitao Wang², Shuhong Liu¹, Yunsong Xu¹, Zhirong Zhang³, Ying Song¹, Zhongping Yao⁴

Affiliations

¹ School of Chemistry and Chemical Engineering, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150001, China.
² Ningbo Key Laboratory of Green Petrochemical Carbon Emission Reduction Technology and Equipment, Zhejiang Institute of Tianjin University, Ningbo, 315201, China.
³ School of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng 224051, China.
⁴ School of Chemistry and Chemical Engineering, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150001, China. Electronic address: yaozhongping@hit.edu.cn.

PMID: 38569311
DOI: 10.1016/j.jcis.2024.03.189

Abstract

The Fenton-like activated molecular oxygen technology demonstrates significant potential in the treatment of refractory organic pollutants in wastewater, offering promising development prospects. We prepared a N-doped C-coated copper-based catalyst Cu⁰/NC3-600 through the pyrolysis of Mel-modified Cu-based metal-organic framework (MOF). The results indicate that the degradation of 20 mg/L norfloxacin (NOR) was achieved using 1.0 g/L Cu⁰/NC3-600 across a wide pH range, with a removal rate exceeding 95 % and total organic carbon (TOC) removals approaching 70 % after 60 min at pH 5-11. The nitrogen doping enhances the electronic structure of the carbon material, facilitating the adsorption of molecular oxygen. Additionally, the formed carbon layer effectively prevent copper leaching,contributing to increased stability to a certain extent. Subsequently, we propose the catalytic reaction mechanism for the Cu⁰/NC/air system. Under acidic conditions, Cu⁰/NC3-600 activates molecular oxygen to produce the •O₂^-, which serves as the primary active species for NOR degradation. While in alkaline conditions, the high-valent copper species Cu³⁺ is generated in conjunction with •O₂^-, both working simultaneously for NOR degradation. Furthermore, based on the LC-MS results, we deduced four possible degradation pathways. This work offers a novel perspective on expanding the pH range of copper-based catalysts with excellent ability to activate molecular oxygen for environmental water treatment.

Keywords: Antibiotic degradation; Cu(0)/NC; Fenton-like; Metal-organic framework; Molecular oxygen activation.