Preparation And Properties Of Bismuth-based Photocatalytic Materials

In recent years,with the rapid development of social economy and industry,people are facing some problems,such as energy shortage and environmental pollution,while living a good life.To solve these problems,researchers are trying to use a variety of technologies and methods,including adsorption,membrane separation,microbial degradation,semiconductor photocatalysis and so on,photocatalytic technology has attracted much researchs’attention because of its advantages of simple operation,low price,high efficiency,good stability and no secondary pollution.Titanium dioxide is widely used by researchers as a traditional photocatalytic material,but only ultraviolet light can be absorbed by titanium dioxide,and the proportion of ultraviolet light in sunlight is very small,the Sun’s rays can not be fully used by the titanium dioxide.In order to improve the photocatalytic activity of semiconductor materials in visible light band,it is necessary to find more novel materials and apply them to solve the problems of environment pollution and energy.Bismuth-based materials have the advantages of low cost,non-poisonous,innocuity and so on,and can realize the response in visible light region.Therefore,it is of great significance to study bismuth-based materials with high utilization and good catalytic performance.In this thesis,several photocatalytic materials which can respond to visible light have been prepared,including the following parts:（1）Bi₈V₂O₁₇photocatalyst was successfully prepared by solid-state method and sol-gel method.The differences of Bi₈V₂O₁₇photocatalytic materials prepared by different methods have been analyzed by characterization,and the photocatalytic properties differences of Bi₈V₂O₁₇photocatalytic materials prepared by different methods have been studied by degradation of Methylene blue with Bi₈V₂O₁₇under visible light.In addition,the properties of Bi₈V₂O₁₇prepared by sol-gel method in the field of electrocatalytic hydrogen evolution have been investigated by electrochemical workstation.The results show that Bi₈V₂O₁₇has good potential in the field of photocatalysis and electrocatalysis.（2）Bi₃Ta O₇photocatalytic material has been prepared by solid-state method,and MB can be degraded under visible light.The results show that Bi₃Ta O₇photocatalyst has good photocatalytic activity when it is irradiated by visible light.（3）BiOCl and BiOCl-PVP photocatalytic materials have been successfully synthesized by solvothermal method.The addition of PVP can control the morphology and size of the materials,making the nanosheets thinner and exposing more highly active crystal planes.Rhodamine B（Rh B）was degraded by the prepared materials under visible light irradiation.The experimental results show that both materials exhibit excellent visible light photocatalytic activity,this indicates that both Bi OCl and Bi OCl-PVP have the potential to be used as visible light photocatalytic materials.（4）BiOBr photocatalytic materials have been successfully prepared by hydrothermal method and solvothermal method at different temperatures.Under visible light irradiation,the materials are used to degrade Rh B under different conditions,the differences of photocatalytic properties among the materials prepared by different reaction conditions can be observed.The results of degradation experiments show that the materials synthesized by different methods all exhibit excellent photocatalytic activity under visible light irradiation,which also proves that Bi OBr materials can be used as visible light photocatalytic materials to degrade organic pollutants.The material synthesized by solvothermal method（the reaction temperature is160℃）has the best degradation effect..