Bi₂O₂CO₃/Ti₃C₂ Photocatalytic Composites Preparation Of Tetracycline And Its Degradation Performance Of Tetracycline In Water

In this thesis,from the perspective of improving the photocatalytic performance of Bi₂O₂CO₃（BOC）semiconductor materials and the response to visible light,using the independent physical and chemical properties of MXene（Ti₃C₂）as an electronic carrier,a BOC/Ti₃C₂composite photocatalytic material was designed and constructed.Tetracycline（TC）,chlortetracycline（CTC）,oxytetracycline（OTC）and their mixtures were used as target water pollutants to study the visible light catalytic performance of the materials.And with the help of experimental methods such as liquid-mass spectrometry（HPLC-MS）,the mechanism of the degradation reaction is discussed in depth,which provides a feasible experimental method and theoretical basis for the construction of BOC high-efficiency photocatalytic materials.The main findings are as follows:1)BOC/Ti₃C₂composite photocatalyst was prepared by hydrothermal method.Scanning electron microscopy（SEM）and transmission electron microscopy（TEM）analysis revealed that the Ti₃C₂surface was successfully loaded with two-dimensional flake BOC.X-ray diffraction（XRD）,Fourier infrared（FT-IR）,X-ray photoelectron spectroscopy（XPS）characterize the chemical form of the material.The study found that in the composite material,photogenerated electrons are transferred from BOC to the Ti₃C₂surface,which is conducive to the separation of photogenerated carriers.The analysis results of ultraviolet-visible diffuse reflectance absorption spectroscopy（DRS）and light fluorescence spectroscopy（PL）show that the band gap of BOC/Ti₃C₂composite material is narrowed,further proving that the combination of the two can improve the visible light absorption capacity of BOC.2)By degrading the target product,the photocatalytic activity of the composite material was studied.The results show that the composite material has high catalytic activity for the three antibiotics.The degradation efficiency of TC,CTC,and OTC are82%,76%,and 75%,respectively,which is much higher than that of the single material BOC for TC（45%）,CTC（45%）and OTC（35%）degradation efficiency.At the same time,the effects of different reaction factors（catalyst dosage,initial concentration of pollutants and initial p H）on the degradation effect were discussed,and kinetic analysis was carried out.In addition,the study also found that the prepared composite material also has high photocatalytic degradation activity for complex mixed antibiotics.3)Using trapping experiments and electron spin resonance（ERS）to verify that the main active substances are photo-generated holes and superoxide radicals,in view of this,the photocatalytic degradation mechanism of BOC/Ti₃C₂is derived.In addition,the reaction paths of TC,CTC,and OTC are analyzed:under the action of active substances,the reaction processes such as oxidation,ring opening,demethylation,deamination,dehydration,etc.form intermediate products.Finally,these intermediate products are further degraded into small molecules..