Study On Preparation And Photocatalytic Properties Of Bismuth Vanadate/Silver Halide Composites

In recent years,photocatalytic technology is considered to be a promising technology for purifying water and clean energy.Bismuth vanadate?BiVO4?is a kind of photocatalytic material with strong photoreactivity in the visible light region,and it has the advantages of non-toxicity,harmlessness and good stability.It has become an important hot spot in the field of environmental science research.However,the poor adsorption capacity of BiVO4 and the easy recombination of photogenerated electron-hole pairs still restrict its photocatalytic performance.As a new type of photocatalytic material,silver halide has obvious plasmon resonance effect in the visible range and shows good activity in photocatalytic degradation of organic pollutants.And caused people to pay attention.And the AgX/Ag?X=Cl,Br,I?system has extraordinary stability and high photocatalytic activity.For this reason,study on preparation and photocatalytic properties of bismuth vanadate/silver halide composites are as follows:In this paper,{040}-BiVO₄ composite oxide and AgX/Ag/{040}-BiVO₄composite photocatalysts with different silver halide composites were prepared by hydrothermal method.The materials were characterized by SEM,XRD,UV-Vis and other analytical methods,and the prepared composites were used for photocatalytic degradation of Rhodamine B.The effects of photocatalytic material morphology,crystal structure and band structure on light absorption properties and photocatalytic degradation of rhodamine B were investigated.The results show that the prepared{040}-BiVO₄ oxide material exists in a monoclinic phase,has good light absorption properties and a suitable energy band structure,and its photocatalytic degradation of rhodamine B is also good.The pH value during preparation has a great influence on the crystal phase composition,structure,morphology,light absorption properties and photocatalytic degradation of rhodamine B of{040}-BiVO₄.When the pH value of the preparation process is 2,the prepared photocatalytic material has high photocatalytic performance,which is related to the crystal phase structure,surface morphology,and light absorption property of the material.After loading AgCl/Ag,AgBr/Ag and AgI/Ag,experimental data shows that the photocatalyst material has better photocatalytic activity than monomer{040}-BiVO₄,which proves that AgCl/Ag,AgBr/Ag and AgI/Ag are supported.The surface of the semiconductor helps to increase the activity of the catalyst,and AgI/Ag/{040}-BiVO₄is the most efficient and time-consuming.It is proved that the heterojunction structure between{040}-BiVO₄ and AgX/Ag is essential for improving the light absorption properties,charge transport rate and photogenerated electron-hole separation during the degradation of Rhodamine B under illumination.