Preparation And Photocatalytic Performance Of Bismuth Based Semiconductor Composites

Photocatalysis to degrade organic pollutants is a emerging technology for water purification,which is based on catalysis technology and utilizes solar energy to degrade soluble organic pollutants.Among various materials,semiconductors have attracted much attention due to their many advantages such as low cost,easy to synthesis,non-toxic,adjustable bandgap,stable physical and chemical properties,etc.And among various semiconductors,bismuth based materials are promising materials which possess many excellent properties such as relatively narrow bandgap,great response for visible light,suitable bandgap edge,non-toxic and non-polluted,etc.However,due to the poor performance of adsorption,poor transfer capacity of photo-generated carriers and fast recombination of photo-generated electron-hole pairs,the photocatalytic performance of single bismuth based materials is not satisfactory.Based on these problems,in this paper,bismuth vanandate was used as a substrate for further modification of other semiconductor materials,and Rh B was used as a simulated organic pollutant to study the visible light photocatalytic performance and mechanism of as-prepared nanocomposites;Designed and synthesized Bi OCl/Bi₂O₂CO₃composites with proper morphologies,and MG was used as a simulated organic pollutant to study the photocatalytic performance and mechanism of as-prepared composites under stimulated sun light irradiation.The main results and experimental details are as follows:1.Pristine Bi VO₄with exposed specific（010）and（110）fact was synthesized by hydrothermal method and Cu₃Mo₂O₉was successfully deposited on the surface of Bi VO₄to construct Cu₃Mo₂O₉/Bi VO₄p-n heterojuction.Photocatalytic experiments demonstrated that the optimal content of Cu₃Mo₂O₉is 5 wt%,and the degradation of Rh B reached 83.6%in 120min under visible light irradiation.At the same time,the analysis of photocatalytic mechanism indicated that the construction of p-n heterojuction could effectively suppress the recombination and enhance transfer capacity of photo-generated electron-hole pairs so as to enhance the photocatalytic performance.Recycle experiments indicated that Cu₃Mo₂O₉/Bi VO₄composites possessed stable recycle performance.2.Pristine Bi VO₄with exposed specific（010）and（110）fact was synthesized by hydrothermal method followed by precipitation of Zn Fe₂O₄to construct Zn Fe₂O₄/Bi VO₄n-n heterojuction.Photocatalytic experiments demonstrated that the composite with 7.5 wt%Zn Fe₂O₄showed highest photocatalytic performance for Rh B degradation under visible light irradiation,and the degradation rate reached 98.0%in 120 min.The analysis of photocatalytic mechanism demonstrated that the construction of n-n heterojuction could effectively suppress the recombination and enhance transfer capacity of photo-generated electron-hole pairs so as to enhance the photocatalytic performance.Recycle experiments indicated that Zn Fe₂O₄/Bi VO₄composites possessed great recycled stability.3.Bi OCl/Bi₂O₂CO₃composites were synthesized by one step hydrothermal method.Photocatalytic experiments demonstrated that the optimal mole ratio of Bi OCl/Bi₂O₂CO₃is1:4,and the photocatalyst can degrade 74.1%of MG in 60 min under stimulated sun light irradiation.The analysis of photocatalytic mechanism indicated that Bi OCl/Bi₂O₂CO₃composites with proper morphologies could enhance the adsorption of dye,effectively suppress the recombination of photo-generated electron-hole pairs and narrow the bandgap so as to enhance the photocatalytic performance.Recycle experiments indicated that Bi OCl/Bi₂O₂CO₃composites possessed stable recycle performance.