The Preparation Of Ag/AgI Bismuth Composite Materials And Visible Light Photocatalytic Properties Research

Along with the development of global economic process,the energy crisis and global environment pollution become more and more serious.Environmental issues have already become one of the most important problems.Photocatalytic technology,as a member of advanced oxidation technology and a typical representative of green chemistry,has aroused tremendous interest.TiO2,as a traditional photocatalyst,has two disadvantages of easy recombination of photogenerated charge carriers and weak visible light absorption ability.The Bi-based materials have attracted considerable attention because of the special electronic structure,outstanding optical properties and good photocatalytic performance.Ag/AgX as the new photocatalyst,due to the obvious surface plasmon resonance(SPR)effect in the visible light region,exhibited high photocatalytic activity for the degradation of organic pollutants under visible light irradiation.Thus,in this paper,the modifications of Bi-based materials photocatalyst were carried out by loading Ag/AgX(X=Cl,Br),two kinds of composite photocatalytic materials AgI/Ag/Bi2MoO6 and AgI/Ag/Bi2O2CO3 were prepared.According to the results,comparing the Bi2MoO6 and Bi2O2CO3,the AgI/Ag/Bi2MoO6-15%and AgI/Ag/Bi2O2CO3-15%excibit excellent photocatalytic performance.The results indicate that are thanks to the introduction of Ag/AgI nanoparticles.In this paper,the AgI/Ag/Bi2MoO6 and AgI/Ag/Bi2O2CO3 photocatalyst were successfully synthesized by a facile hydrothermal method combined with an ultrasonic-assisted precipitation-photoreduction technique.X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and UV-vis diffuse reflectance spectroscopy(DRS)analysis were employed to characterize the composition,phase structures,crystallinity,morphologies and optical properties of the obtained catalystsThe main results as follows:1.The AgI/Ag/Bi2O2CO3 and AgI/Ag/Bi2MoO6 composites were successfully prepared via a hydrothermal method.The ratio of Ag was found to influence the photocatalytic performance.2.The photocatalytic performance of AgI/Ag/Bi2O2CO3 and AgI/Ag/Bi2MoO6 were evaluated through the degradation of rhodamine-B(Rh-B),methylene blue(MB)and methyl orange(MO)aqueous solution under visible-light irradiation.3.On the basis of active species trapping experimental results and band structure analysis,different photocatalytic mechanisms are proposed by organic pollutants degradation.According to the results.The excellent photocatalytic performance of the AgI/Ag/Bi2MoO6 photocatalysts can be ascribed to the Z-scheme system.The active species in photocatalytic degradation over AgI/Ag/B2MoO6 and AgI/Ag/Bi2O2CO3 are found to be h+·OH and ·O2-.h+ and ·O2-are the significant active species as main reactive species for Agl/Ag/Bi2MoO6 and AgI/Ag/Bi2O2CO3.