The Construction Of Graphite Felt Cathode Modified By MOFs Derivatives And Study On Electro-fenton Performance To Degrade Typital Antibiotics

With the continuous detection of antibiotics in different water bodies,the water pollution caused by antibiotics has been obtained more and more attention.Due to antibiotics’s high toxicity and low biodegradability,it is difficult to achieve the ideal removal effect by most treatment methods at present.Electro-Fenton technology is an electrochemical advanced oxidation technology,which can effectively remove the refractory organic pollutants in wastewater.The heterogeneous electro-Fenton system can effectively overcome the shortcomings of traditional homogeneous system,such as narrow applied p H and iron sludge pollution.The composite of catalyst and carbon cathode can enhance the in-situ utilization of H₂O₂ and improve the recycling efficiency of catalyst.Based on this,in this subject,metal organic frameworks（MOFs）were used as precursors to prepare two binder-free modified graphite felt cathodes with MOFs derivatives by in-situ hydrothermal method.Metal doping was used to adjust the electron configuration.The catalytic performance and mechanism of electro-Fenton degradation of typital antibiotics were further studied.First,a series of manganese/cobalt MOFs derivatives modified graphite felt cathodes(Mn_xCo_3-x@C-GF)were synthesized,and used to treat ciprofloxacin.By adjusting the metal ratio in the precursor,the influence on the structure and electrochemical properties of cathode material was analyzed.The morphology of the catalyst could be effectively controlled.It was found that when Mn:Co was 2:1,the prepared catalyst had the largest specific surface area and good pore structure.The interaction between metals could enhance electrochemical activity,reduce charge resistance and promote redox circulation.The electro-Fenton degradation behaviour of CIP under different reaction parameters were studied.When the p H was 3 and the current was 20 m A,99.8%of CIP could be removed.The degradation pathway and mechanism of CIP were proposed through EPR and LC-MS analysis.The results showed that the mesoporous structure derived from the MOFs and Mn^2+/3+/4+and Co^2+/3+redox pairs significantly enhanced the mass exchange and interface electron transfer,thereby accelerating the production of·OH and improving the catalytic degradation capability of cathode.In order to fix the dissolved Fe²⁺,a highly efficient and stable graphite felt electrode modified with cerium-iron MOFs derivative（Ce/Fe@NPC-GF）was prepared.It was used to degrade sulfamethoxazole（SMX）in a heterogeneous electro-Fenton system.The results showed that when the 10%Ce was added,the catalyst displayed a flower-like structure composed of nanosheets,which provided abundant active sites for the catalytic reaction.The enhanced carbon defects and hydrophilicity could promote the occurrence of ORR reaction.The multivalent cerium-iron metal elements and the highly active oxygen Oαcomponent effectively enhanced the electrocatalytic activity.Under the optimal conditions of p H 3,SMX could be basically degraded within 120 min when 20 m A current was applied The removal efficiency was good in a wide p H range.After 8 cycles,the electrode could still maintain high stability and excellent catalytic ability,as evidenced by SEM and XRD.Through LC-MS detection of degradation intermediates,five degradation pathways of SMX were deduced.Finally,the catalytic activation mechanism of Ce/Fe@NPC-GF was further analyzed through free radical identification experiments and XPS.It was proposed that Ce could be used as“electron accelerating agent”to promote the electron transfer rate and Fe^Ⅱregeneration.The in-situ H₂O₂ production and decomposition were enhanced,thereby increasing the degradation rate of pollutants.