Carbon shell derived from bottle waste PET on α-Fe2O3/Fe3O4 heterostructure core as synergetic Fenton-like catalyst for degradation of antibiotics

In this work, two approaches to environmental sustainability have been followed including the synthesis of an efficient and easily recyclable catalyst for Fenton-like degradation of antibiotics from water, and the upcycling of waste polyethylene terephthalate (PET) into the value-added product through a feasible procedure. For this purpose, the Fe2O3/Fe3O4 mixture coated by the carbon layer derived from the bottle waste PET was synthesized for boosting the Fe3+/Fe2+ cycle in the Fenton-like reaction. The FeCl3 can act as a catalyst for graphitization process and also the precursor of metal oxide nanoparticles. The catalytic efficiency was evaluated for the degradation reaction of amoxicillin and azithromycin antibiotics. Complete conversion of amoxicillin and azithromycin (15 mg/L) was observed in the presence of 5 mu L of H2O2, at pH=3 for 30 min. Also, the mineralization of amoxicillin and azithromycin was evaluated by TOC analysis, which was obtained as 77 and 89 %, respectively. The high activity of the catalyst can be attributed to the presence of a mixture of iron oxide nanoparticles for the catalysis of Fenton-like reactions and activation of H2O2, as well as the coating of nanoparticles with a carbon layer to stabilize and prevent metal leakage and contamination of the mixture. In addition, due to the good electrical conductivity of carbon layer, it can act as electron donors to enhance Fe3+ reduction.