Degradation of norfloxacin by CoFe alloy nanoparticles encapsulated in nitrogen doped graphitic carbon (CoFe@N-GC) activated peroxymonosulfate

Developing carbon-based hybrid catalysts with high reactivity, good stability, and low cost is critical for environmental remediation via heterogeneous advanced oxidation processes (AOPs). In this work, CoFe alloy particles encapsulated in nitrogen doped graphitic carbon (donated as CoFe@N-GC), in situ converted from cobalt modified Prussian blue (PB) precursor through a two-step carbonization route, is rationally designed and synthesized as an advanced catalyst for the degradation of antibiotics norfloxacin (NOF) by coupling with peroxymonosulfate (PMS). The resultant hybrid catalyst can not only offer a conductive network that promotes the electron transfer but also protect the metal species from being leached out. By serving as a catalyst/activator, it shows an outperforming performance in catalytic degradation of organic pollutants than other catalysts (i.e. CuO, CoFe2O4, and biochar). The electron paramagnetic resonance (EPR) results clearly reveal that the sulfate radicals (SO4•−) and singlet oxygen (1O2) are the dominant reactive oxidative species (ROS). After four successive cycles, CoFe@N-GC still performs excellent catalytic activity, leading to a NOF degradation of 94.4% within 20 min ([NOF] = 15 µM, [PMS] = 0.2 mM, [Catalyst] = 0.05 g L−1, pH = 6.0). This study highlights the in situ synthesis of CoFe@N-GC with outstanding activities for catalytic degradation of organic pollutants.