Preparation Of GO/Ag/BiOX(x=Br,I)composite Photocatalyst And Performance For Degradation Of Rhodamine B Wastewater

In China,the printing and dyeing industry has always occupied an important proportion in the national economy.In recent years,with the advancement in science and technology,the acceleration of industrialization has led to rapid development of the dye industry.At the same time,the discharge of dyestuff wastewater has followed.Increasingly.Since dye wastewater contains a large amount of toxic and hazardous substances,and these substances are difficult to be degraded by organisms,once untreated or under-treated pollutants are discharged into water bodies,they pose a great threat to the surrounding environment and human health.Compared with traditional water treatment technologies,photocatalytic technology,as an advanced oxidation technology,can decompose hard-to-degrade dye macromolecules into small organic molecules or completely degrade to CO₂,H₂O and inorganic ions.At the same time,photocatalytic technology also has Due to the high degradation efficiency of pollutants,no secondary pollution and low energy consumption,the research of new photocatalytic materials has become a research hotspot for researchers.Among the many photocatalytic materials,yttrium oxyhalide has become our research focus because of its unique layered structure,good optical and electrical properties.This dissertation intends to use BiOBr and BiOI as research bases to construct GO/Ag/BiOBr and GO/Ag/BiOI composite catalyst systems by doping noble metal Ag and nonmetal GO,and use xenon lamp to simulate visible light source to Rhodamine B.For the target pollutants,the catalytic activity of the two new catalysts was investigated through degradation experiments.The catalyst materials were characterized and analyzed by a series of characterization methods such as XRD,SEM,TEM,XPS,FT-IR and UV vis-DRS.The results show that the optimal doping ratio of the new composite catalyst material is GO/Ag/BiOBr（2wt%GO,1.5wt%Ag）and GO/Ag/BiOI（2wt%GO,1.5wt%Ag）.In this optimal proportion of doping experiments,the photocatalytic activity of BiOBr and BiOI catalyst materials was significantly enhanced due to the addition of metallic Ag and non-metallic GO.This is due to the Schottky barrier,surface plasmon resonance and good electrical conductivity of metallic Ag,the large specific surface area of non-metallic GO and the excellent electron transfer efficiency,which,in combination,promotes the photo-generated carriers of the catalyst material.The transfer and separation effectively limit the probability of photoelectron-hole recombination,thereby effectively enhancing the photocatalytic activity of the catalyst material.The two new composite catalysts show a high degradation rate during the degradation of rhodamine B.In the subsequent repetitive experiments of the catalyst materials,the catalyst still showed good photocatalytic activity and stability after repeated use for 5 times,indicating that the new composite catalyst material has good stability and reusability value.In summary,in this paper,the existing BiOX（Br,I）was modified by metallic Ag and non-metallic GO to modify the photoelectric properties of the new GO/Ag/BiOBr and GO/Ag.The /BiOI composite catalyst has higher photocatalytic activity and stability.