Preparation And Properties Research Of BiOIO₃/BiOBr And AgI/CdMoO₄ Photocatalysts

Energy crisis and environmental deterioration have become more and more severe on a global scale.In this situation,photocatalytic technology,which can solve these two problems,is showing a good application prospects.As the core part of the photocatalytic technical field,to research and develop visible-light-driven photocatalysts with good activity has become the difficuties and hot spots in this field.In this paper,we fabricate two kinds of visible-light-driven photocatalysts BiOIO₃/BiOBr and AgI/CdMoO₄ on the basis of the researching on bismuth-based photocatalytic materials,molybdate photocatalytic materials and silver halide photocatalyst materials.The photocatalysts were characterized by XRD,SEM,TEM,HRTEM,XPS,UV-vis DRS,N₂ adsorption-desorption,PL and photocurrents to investigate the crystallinity,morphology and optical properties.We used the organic dyes as the target pollutants to evaluate the photocatalytic activities of the composites.Meanwhile,we also analyzed the possible photocatalytic mechanism with the help of all the characterization results.The first chapter mainly introduced the development of the semiconductor photocatalytic technology,the mechanism and application of photocatalytic technology.Then we introdued the modification methods of photocatalysts in current years.We also introduced some photocatalysts and their current research status.The second chapter mainly introduced the fabrication of BiOIO₃/BiOBr and its visible light photocatalytic activity.We synthesized the composites by using a hydrothermal method combined with a facile chemical precipitation method.The photocatalytic activities and recycle experiment of the samples with different BiOIO₃ molar ratio were evaluated by photodecomposition of RhB.The result showed that the lI/6Br composite possessed the best performance and stability.In order to evaluate the extensive adaptability of the sample,they were further used to degrade CV,MO and MB.Finally,we tried to understand the possible photocatalytic mechanism with the help of active species trapping measurements,characterization and the band position analysis of the composites.It can be seen from the results that the light absorption range of the composite extends to the visible region,the main active groups in the photocatalytic system are the h⁺ and the superoxide radical,and the photo-generated electron-hole separation efficiency of the composite is better than that of the monomer?The last chapter of the paper mainly introduced the fabrication of AgI/CdMoO₄ and its visible light photocatalytic activity.The composite was fabricated via a hydrothermal process combined with a facile deposition-precipitation method at room temperature.The obtained samples were characterized using various analytical techniques.In the photocatalytic activity experments,we used RhB as the target pollutants to investigate the photocatalytic activity and recyclability of AgI/CdMoO₄ composites with different mass ratios.With the help of active species trapping measurements and band position analysis,we put forward the possible photocatalytic mechanism of the composites.It can be seen from the results that the light absorption range of the prepared composite is extended to the visible region,and the holes and superoxide radical are the main active groups in the photocatalytic process,and the photo electron-hole separation efficiency of the composite is obviously enhanced.Finally,we summarized the contents of this paper and made a prospect for our future research work.