Efficient Activation Of Peroxymonosulfate by Cobalt And Nitrogen-Doped Porous Carbon For Perfluorooctanoic Acid Degradation: The Synergism Performance and Mechanism Of Co and N

In this study, a precursor (ZIF-67) was selected to prepare Co and N codoped porous carbon (Co@NPC) for activated permonosulfate (PMS) degradation of perfluorooctanoic acid. In Co@NPC/PMS system, at pH 7, 0.3g/L catalyst and 0.1mM PMS were added, respectively, and PFOA was effectively degraded in 140 minutes. Compared with the NPC/PMS system, the degradation ability is significantly improved. The morphology, crystal form and composition were studied by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and other methods. Through free radical quenching experiments and electron paramagnetic resonance (ESR) experiments, the degradation performance of the catalyst to PFOA was investigated, and the types of free radicals in the system were revealed. The catalytic mechanism and active sites of PFOA were analyzed by high performance liquid chromatography- mass spectrometry determination. During the experiment, the optimal degradation conditions were explored, including carbonization temperature, pH, PMS concentration and catalyst dosage. Introducing codoping of cobalt and nitrogen into carbon-based materials can synergistically enhance the catalytic activity of PMS. At the same time, the core-shell structure of NPC coated cobalt metal also has the characteristics of improving the electron transfer ability of carbon, promoting the mass transfer of reactants, and preventing cobalt metal agglomeration and metal dissolution. The above results indicate that the Co@NPC/PMS system has potential application value in practical wastewater treatment.