Preparation And Performance Study Of BiOX/GO/MOF-5 Photocatalysts

As a newly developed two-dimensional material,since BiOX?X=Cl,Br,I?possesses several advantages like the wider visible light response region and the better conductivity,which it has become a hot spot in recent research.However,owing to its inherent defects such as photoinduced corrosion,small particle size and easy agglomeration,so it is unable to produce on a large scale in reality.Therefore,this project aims to prepare a new type of composite photocatalyst BiOX/GO/MOF-5 for further processing of complex pollutants based on the poor catalytic performance of traditional catalysts.The morphology and structure of BiOX series photocatalysts were characterized by XRD,SEM,TEM and UV-Vis DRS.And the photocatalytic degradation of RhB were carried out to evaluate their photocatalytic performance.1.Taking BiOX as the main research object,the sheet-like BiOX photocatalyst was prepared by improving the traditional hydrothermal method.The results show that BiOBr and BiOCl all exhibited a good two-dimensional morphology.Therefore,BiOBr and BiOCl photocatalysts are mainly selected as the composite host material.And although to some extent,two-dimensional BiOX can degrade the pollutants,it can be clearly found that the specific surface area and photocatalytic activity of a single two-dimensional catalyst are limited,the degradation rate of BiOCl is 40%in 120 min.Under the same experimental conditions,the degradation efficiency of BiOBr nanosheets to RhB is 45%.2.A novel two-dimensional photocatalyst BiOCl/GO were successfully synthesized via a facile ultrasonic assisted method.The results showed that BiOCl/GO photocatalyst system exhibited significantly enhanced photocatalytic performance as compared with pure BiOCl.Moreover,it can be clearly found that the prepared materials all present a good two-dimensional morphology.When the loading of GO is 4%,the catalyst dosage is 1 g/L,which shows the optimal photocatalytic activity,the degrading rate of RhB was 69%in 120min.Additionally,BiOCl/GO sample was stable during the recycled photocatalytic experiment,implying a potential practicability in future applications.3.Taking BiOX/GO/MOF-5 as the main research object.The XRD,SEM,TEM and UV-Vis DRS were employed to characterize the phase structures and morphologie of the ternary composite photocatalysts.The results showed that the sheet-like structure of two-dimensional morphology was successfully prepared by ultrasonic assisted method.Compared with the single catalyst,the absorption range of the photocatalysts in the visible light region is expanded after the composite,and the specific surface area and photocatalytic performance of the catalyst are also significantly improved.The photocatalytic activities and mechanism of these photocatalysts were evaluated and discussed by photocatalytic degradation of RhB.Under visible light,the degradation efficiency of ternary photocatalysis at 120 min can reach 98.7%.And it also shows that·O₂^-plays a major role in photocatalytic reactions.The main work of this thesis is to improve the photocatalytic activity of the catalyst by modifying the BiOX material.The prepared materials have the characteristics of green color,high degradation efficiency,high light utilization efficiency,and are of great significance in solving the increasingly serious resource shortage and environmental pollution.