Preparation Of Copper-based Bimetallic Oxides And Their Catalytic Degradation Of Organic Matter By Hydrogen Peroxide

Fenton-like catalysis in Advanced Oxidation Processes（AOPs）is a highly efficient and oxidising technology,but it also suffers from a narrow p H range,low H₂O₂ utilisation and the inability to recycle the active component.Therefore,it is crucial to research and develop a new and efficient multiphase Fenton-like catalyst.Compared with iron-based catalysts,copper-based Fenton-like catalysts offer excellent performance over a wider p H range.In this thesis,Cu-Al₂O₃ catalyst,Cu-Al₂O₃@PVDF catalytic membrane and Cu-Al₂O₃-N catalyst were designed and synthesized.With BPA as the target pollutant,the catalytic properties of the three materials were investigated and their reaction mechanism was analyzed.It mainly includes the following contents:（1）Three copper-based bimetallic oxides,Cu-Al,Cu-Fe and Cu-Zn were synthesized by hydrothermal method and used to catalyze the degradation of BPA by H₂O₂,respectively.The results showed that the Cu-Al bimetallic materials were the most effective in the removal of BPA.When the Cu content was 7.8%,the Cu-Al bimetallic materials could degrade and remove more than 90%of BPA within 90 min,which has the highest catalytic activity.The characterization results showed that the Cu-Al bimetallic material has an internal Cu-Al₂O₃ structure,leading to the formation of the electron-rich center of Cu,which facilitated the reduction of Cu²⁺to Cu⁺and promoted the selective conversion of H₂O₂ to·OH.It is found that Cu-Al₂O₃ catalyst has high catalytic activity in the p H range of 5-9,which broadens the p H range of Fenton-like reaction.Moreover,the BPA removal rate of 70.9%was still achieved after ten cycles,demonstrating the good cycling stability of the Cu-Al₂O₃ catalyst.（2）Cu-Al₂O₃ catalyst can effectively remove BPA,but the powdered catalyst requires centrifugation,filtration,washing and drying steps to be recycled,and there are also problems such as catalyst loss and secondary contamination.On this basis,Cu-Al₂O₃@PVDF catalytic membranes were prepared using electrostatic spinning technology.Using XRD,SEM,BET and FTIR characterization,it was demonstrated that Cu-Al₂O₃ was successfully added to the PVDF membrane.About 42%of BPA could be adsorbed using this catalytic membrane,and 90%of BPA could be degraded and removed after the addition of H₂O₂ for 90 min,proving that the catalytic membrane could achieve the purpose of adsorption and enrichment of BPA and degradation.The EPR characterization revealed that the catalytic membrane does not only produce·OH but also ~1O₂ as one of the main active substances,and that the Cu-Al₂O₃@PVDF membrane has high catalytic activity.At the same time,when recycling,the catalytic membrane can be directly removed,cleaned and then continue to participate in the reaction,greatly increasing the possibility of application in practical production.（3）The doping of N atoms can promote the ion exchange activity and catalytic ability of the material for redox reactions.The Cu-Al₂O₃ catalyst with a Cu content of7.8%only achieved 90%BPA removal in 90 min at neutral p H with a kinetic constant of 0.027 min^-1,whereas the Cu-Al₂O₃-N catalyst prepared with the addition of 2,1,3-benzothiadiazole achieved 80%BPA removal in 30 min with a kinetic constant of0.038 min^-1.Compared with Cu-Al₂O₃ catalyst,this catalyst has higher catalytic activity.After ten cycles,the removal rate was still 82.08%,demonstrating the catalyst is stable.Analysis of the catalytic principles by XRD,BET,TEM,SEM,FTIR and electrochemical characterization revealed that the doped N formed Cu-Nx active centers with Cu,which could also generate reaction centroids with H₂O₂ to accelerate electron transfer,ensuring high catalytic activity throughout the cycling process.