Nitrogen-doped carbon-coated Cu 0 activates molecular oxygen for norfloxacin degradation over a wide pH range

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 Cu 0 /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 Cu 0 /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 Cu 0 /NC/air system. Under acidic conditions, Cu 0 /NC3-600 activates molecular oxygen to produce the center dot O 2 - , which serves as the primary active species for NOR degradation. While in alkaline conditions, the high-valent copper species Cu 3 + is generated in conjunction with center dot O 2 - , 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.