Superoxide radical mediated persulfate activation by nitrogen doped bimetallic MOF (FeCo/N-MOF) for efficient tetracycline degradation

Metal organic frameworks (MOFs) have been widely concerned by researchers as catalytic materials. In this work, nitrogen doped Fe, Co bimetallic MOF named FeCo/N-MOF was prepared by one-pot hydrothermal method as a catalyst for activating persulfate to degrade tetracycline. The hexagonal spindle crystals morphology and porous structure were observed on the FeCo/N-MOF. The X-ray photoelectron spectroscopy (XPS) showed that Fe(III) and Co(II) were the main active sites and the presence of pyrrole N was positive to the catalysis. The different conditions of catalyst dosage, pH and persulfate concentration were discussed to further understand the mechanism of FeCo/N-MOF on tetracycline (TC) degradation. The results revealed that about 99% of tetracycline was degraded in 150 min when FeCo/N-MOF was 0.4 g/L and persulfate was 5 mmol/L in a wide range of pH from 3 to 9. Moreover, the reaction stoichiometric efficiency of persulfate was 6.13%. There were radicals and non-radical pathways in the process of TC degradation and the superoxide radical was the main active sub-stances. This study suggested that FeCo/N-MOF was of great potential in persulfate activation for water puri-fication, which also provided a platform for MOF-derived catalysts in the field of advanced oxidation.

Automated summary

In this study, a nitrogen doped Fe, Co bimetallic MOF named FeCo/N-MOF was prepared and investigated as a catalyst for degrading tetracycline. The results showed that FeCo/N-MOF had high efficiency in degrading tetracycline, with about 99% degradation achieved in 150 minutes. The reaction stoichiometric efficiency of persulfate was found to be 6.13%. This study highlights the potential of FeCo/N-MOF as a catalyst for water purification and provides insights into the field of MOF-derived catalysts in advanced oxidation.