Preparation Of Bismuth Tungstate/Metal Organic Framework Composite Material And Study On Its Photocatalytic Performance

With the rapid development of the industrial economy,the issue of water pollution,which mainly consists of the industrial wastewater and domestic wastewater,seriously threatens the ecological environment for our humans depend.However,traditional wastewater treatment processes are mainly used to treat ordinary industrial wastewater.It is costly and prone to secondary pollution to the environment.Semiconductor photocatalyst technology is gaining widespread attention due to its many advantages,including the use of clean energy solar energy,a simple process,and the absence of secondary pollution.Among them,bismuth tungstate(Bi₂WO₆),as the most popular bismuth-based photocatalytic semiconductor material in recent years,has become a research hotspot for many scholars.However,pure Bi₂WO₆ material still has a series of problems,mainly including photo-generated electrons-hole pairs are easy to recombine,resulting in low degradation efficiency,and the material has a small specific surface area and is difficult to adsorb pollutants.These problems severely limit the further development of the pure Bi₂WO₆ material in practical applications.Therefore,this study used Bi₂WO₆ materials and metal organic framework materials to construct heterostructure modification work in order to increase the specific surface area of the pure Bi₂WO₆ material and improve the photocatalytic performance of the material.The main research contents are as follows:(1)In this study,Bi₂WO₆/UiO-66 composite photocatalytic nanomaterials were successfully synthesized by a simple solvothermal method.XRD,FTIR,SEM and other characterization methods have confirmed that Bi₂WO₆ and Ui O-66 have successfully constructed a heterostructure,and the prepared composite material has a good micro morphology and high crystallinity.In addition,UV-vis DRS,BET,PL and other characterization methods were used to test the optical properties,specific surface area and separation efficiency of photo-generated carriers of the composite materials.In this experiment,the organic dye Rhodamine B(Rh B)was selected as the target degradation pollutant to evaluate the photocatalytic degradation performance of the prepared composite photocatalytic material.Based on the above characterization results,it is found that the specific surface area and the photocatalytic performance of the BU series composite material is significantly better than that of the pure Bi₂WO₆ material,the reaction rate constant is about 2.97 times that of the pure Bi₂WO₆ material,and the composite material has good cycle stability.(2)This research continues to explore after the successful preparation of BU series composite materials,and uses a simple solvothermal method to design and prepare Bi₂WO₆/Ui O-66-NH₂ composite photocatalytic materials.Through the analysis of XRD,FTIR,SEM-EDS and TEM and other characterization methods,the successful composite of Bi₂WO₆ and Ui O-66-NH₂ material was confirmed.Characterization methods such as UV-vis DRS,BET and PL were used to investigate the light absorption performance,specific surface area and separation efficiency of photogenerated carriers of the composite material.By comparing with the BU series composite materials,it can be seen that the specific surface area and photocatalytic activity of the BUN series composite materials has been significantly improved and improved,and the reaction rate constant is about 3.19 times that of the pure Bi₂WO₆ material,which further confirms the photocatalytic activity of the BUN series composite materials.The catalytic performance was upgraded successfully.After four cycles of stability experiments,the photocatalytic degradation efficiency of the BUN composite material is still above 90%,and it has excellent cycle stability.