Study On The Synthesis Of Bismuth Composite And Its Photodegradation Performance Of Organic Pollutant

In recent years,photodegradation technology has become a research hotspot at China and oversea due to its advantages such as non-toxicity,high efficiency and no second pollution etc.It is of great significance to develop new photocatalyst for the application of photodegradation technology in organic pollutant treatment.With the growth of population and the continuous development of industrialization,more and more organic pollutants are discharged into the environment.In order to improve the quality of water environment,it is necessary to ensure the efficient and economical water treatment technology.In this study,Bismuth photocatalysts were used as the base to prepare new composite catalyst by modifying iron tetroxide(Fe3O4)and graphene oxide(GO),respectively.We aim at fabricating a ternary magnetic recyclable Bi2WO6/BiOI@Fe3O4 composite that could be applied for photodegradation of tetracycline(TC)from synthetic wastewater.To identify any changes with respect to the composite’s morphology and crystal structure properties,XRD,FTIR,FESEM-EDS,PL and VSM analyses are carried out.Effects of Fe3O4 loading ratio on the Bi2WO6/BiOI for TC photodegradation are evaluated,while operational parameters such as pH,reaction time,TC concentration,and photocatalyst’s dose are optimized.Removal mechanisms of the TC by the composite and its photodegradation pathways are elaborated.On the other hand,we also investigate and evaluate the effectiveness of GO@Bi2WO6/BiOI composite as a novel photocatalyst for BPA removal from aqueous solutions under UVvis irradiation.(1)Both Bi2WO6/BiOI@Fe3O4 and GO@Bi2WO6/BiOI photocatalytic composites have been successfully synthesized by "One-step hydrothermal method",which has the advantages of simple operation and low cost.(2)This study prepared the Bi2WO6/BiOI@Fe3O4 composite with vary Fe3O4 loading(2.5%、5%、10%).The characterization analyses of Bi2WO6/BiOI@Fe3O4 show that the Bi2WO6/BiOI@Fe3O4 composites have excellent specific surface area and catalytic performance,which is not a simple physical composite.With respect to its performance,under the same optimized conditions(1 g/L of dose;5 mg/L of TC;pH 7;3 h of reaction time),the Bi2WO6/BiOI@5%Fe3O4 composite has the highest TC removal(97%).(3)After being saturated,the spent photocatalyst could be magnetically separated from solution for subsequent use.In spite of three consecutive cycles with 71%of efficiency,the spent composite still has reasonable photocatalytic activities for reuse.Overall,this suggests that the composite is a promising photocatalyst for TC removal from aqueous solutions.(4)GO@Bi2WO6/BiOI composite has demonstrated its potential as a promising photocatalyst for BPA removal under UV-vis irradiation.About 81%of BPA removal is attained by the GO@Bi2WO6/BiOI under optimized conditions(10 mg/L of BPA;0.5 g/L of dose;pH 7 and 5 h of reaction time).Therefore,this study prepared bismuth-based photocatalyst with good photocatalytic activity by modifying Bi2WO6/iOI.The results provided a new photocatalytic material for water pollution control by studying the properties of organic pollutants treated by the material.