| Electrochemical oxidation technology has been widely used in the treatment of antibiotic wastewater due to its simple operation,low secondary pollution,and high efficiency.PbO2 electrode has broad application prospects and is a typical anode material for effectively treating antibiotic wastewater.However,the PbO2 electrode has drawbacks such as low electrocatalytic activity and instability,which restrict its large-scale industrial application.Therefore,this article uses La and Ce rare earth elements to modify the PbO2 electrode,and combines the micro morphology,crystal structure,and electrochemical performance of the electrode to explore the electrocatalytic activity of the modified electrode.The influence of process parameters on the degradation of ceftazidime,tetracycline,and sulfamethoxazole antibiotics is investigated,and the mechanism and pathway of electrocatalytic degradation of ceftazidime are elucidated and constructed,providing a theoretical basis for the electrocatalytic degradation of antibiotics by PbO2 electrode.The main research content and conclusions are as follows:(1)Ti/SnO2-Sb/PbO2-La electrode was prepared by electrochemical deposition method,and its microstructure was characterized by SEM,XRD,XPS and other methods,and the crystal structure was analyzed The results indicate that after La doping,the number of granular crystals on the electrode surface increases.Combined with electrochemical performance testing,the Ti/SnO2-Sb/PbO2-La electrode showed a high oxygen evolution potential(1.97 VSCE)with obvious oxidation and reduction peaks.The degradation of ceftazidime was carried out using Ti/SnO2-Sb/PbO2 and Ti/SnO2-Sb/PbO2-La electrodes,with removal rates of 85.24%and 96.12%,respectively.The Ti/SnO2-Sb/PbO2-La modified electrode showed good electrocatalytic activity.(2)Ti/SnO2-Sb/PbO2-La-Ce electrodes were prepared by adding La and Ce into PbO2 precipitated fluid.It is observed by SEM that after La and Ce doping,the electrode surface has a cone structure with obvious boundaries,and the surface cracks disappear,exposing more active site.The oxygen evolution potential of Ti/SnO2-Sb/PbO2-La-Ce electrode is 2.55 VSCE,which has a higher oxygen evolution potential than that of Ti/SnO2-Sb/PbO2-La electrode.The test of hydroxyl radical shows that the addition of Ce improves the production capacity of OH.The results of the degradation experiment of ceftazidime showed that the Ti/SnO2-Sb/PbO2-La-Ce electrode had a removal rate of 98.12%for ceftazidime,indicating that the doping of Ce improved the catalytic activity of the electrode and was beneficial for improving the removal rate of ceftazidime.Through free radical validation experiments,it was found that the degradation process of ceftazidime mainly relies on indirect oxidation to produce·OH.By combining UV visible spectroscopy testing,ion chromatography,and high-performance liquid chromatography-mass spectrometry,the intermediate products of the degradation process were analyzed to explore the degradation mechanism of ceftazidime and construct its degradation pathway.(3)The electrocatalytic degradation of tetracycline and sulfamethoxazole was carried out using Ti/SnO2-Sb/PbO2-La-Ce electrodes,and the removal rates under the optimal experimental conditions were 96.89%and 95.46%,respectively.The Ti/SnO2-Sb/PbO2-La-Ce electrode not only has a good removal rate for ceftazidime antibiotics,but also is suitable for the degradation of tetracycline and sulfamethoxazole.This article successfully prepared Ti/SnO2-Sb/PbO2 electrode,Ti/SnO2-Sb/PbO2-La electrode,and Ti/SnO2-Sb/PbO2-La Ce electrode.The Ti/SnO2-Sb/PbO2-La Ce electrode has excellent electrocatalytic activity and stability,and exhibits good remolal effects on ceftazidime,tetracycline,and sulfamethoxazole.Provide a theoretical basis for the electrocatalytic degradation of ceftazidime,tetracycline,and sulfametho-xazole using a new type of PbO2 electrode. |
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