Study on the mechanisms of DMP degradation by electro-Fenton method modified by single atomic-Co doped carbon-based catalyst

Electro-Fenton technology is an advanced oxidation process for phthalic acid esters (PAEs) that builds upon traditional Fenton technology, enhancing its efficiency, selectivity, and flexibility. Thus, cobalt-doped carbon-based catalyst (Co@NSC) were prapered via melamine doped by cobalt (Co) and calcinated at high temperature, and showed excent mesoporous structure (mainly range from 1.3 to 16 nm), high surface area (223.26 m2/g) and big pore volume (0.392 cm3/g). And the result of electrochemical performance test showed that the two-electron oxygen reduction ability of the material can be effectively improved in the case of Co doping. DMP can be degraded within 30 min by using Co@NSC as an electro-Fenton cathode, with excellent degradation efficiency (100 %) and total organic carbon (TOC) mineralization rate (about 40 %) even under the optimal conditions. The exploration of the mechanism demonstrated that OH and 1O2 were the main contributors. According to density functional theory (DFT) theoretical calculation and liquid chromatograph-mass spectrometer(LC-MS) results, the vulnerable site and degradation path of DMP were reasonably speculated. The ecotoxicity evaluation of the degradation products showed that the the toxicity of DMP has been significantly reduced during degradation process by Co@NSC electro-Fenton. Thus, Co@NSC is a cost-effective and promising catalyst, in which all the metal sites were utilized while the cost of metal were significantly minimized.