Insights into the mechanism of enhanced peroxymonosulfate degraded tetracycline using metal organic framework derived carbonyl modified carbon-coated Fe0

Tetracycline (TC) is a commonly used antibiotic that has gained wide spread notoriety owing to its high environmental risks. In this study, rich carbonyl-modified carbon-coated Fe 0 was obtained by pyrolysis of MIL-100(Fe) in an Ar atmosphere, and used to activate peroxymonosulfate (PMS) for the degradation of tetracycline in water. The roles of Fe 0 , carbon and surface carbonyl on PMS activation were investigated. Fe 0 continuously activated PMS, acted as a sustained-release source of Fe 2+ , and could effectively activate PMS to produce SO 4 •− , O 2 •− and •OH. Carbon was found to do responsible for electron transportation during the activation of PMS and slow down the oxidation of Fe 0 . The carbonyl group on the carbon surface layer was the active site of 1 O 2 , which explains the enhanced performance for TC degradation . When Ca = 0.1 g/L and C 0 = 0.4 mM, TC degradation rate reached 96%, which was attributed to the synergistic effect of radicals (i.e., SO 4 •− , O 2 •− , •OH) and non-radical (i.e., 1 O 2 ). Finally, the degradation pathway was proposed by combining density functional theory (DFT) calculations with liquid chromatography-mass spectrometry (LC-MS), toxicities of the intermediate products were also evaluated. All results show that carbonyl-modified carbon-coated Fe 0 possesses promising capacity for the removal of antibiotics from water.