Synthesis And Properties Of Bismuth Oxide Composite Photocatalyst

Since the 21st century,human industry and economy have developed rapidly,which also brought many serious effects on living the environment of human,such as,water pollution,land pollution and air pollution,especially water pollution.Therefore,it is particularly urgent to find suitable method to deal with pollution problems.Nowadays,photocatalytic technology is used to treat water pollution,which has attracted wide attention of researchers.In this paper,BiOBr-based composites were selected as photocatalyst for removal water pollution.The article was divided into three parts:（1）Synthesized and photocatalytic properties of nitrogen-doped graphene quantum dots/BiOX（N-GQDs/BiOX）composites.An efficient photocatalyst consisting of N-GQDs dispersed on the surface of the three-dimensional hierarchical BiOX（X=Br,Cl）was synthesized via a simple solvothermal method,the degradation of organic pollutants by composites with different amounts of N-GQDs was investigated under visible light.The crystal structure,morphology and optical properties of the synthesized catalysts were characterized by XRD,SEM,XPS,DRS and PL.The experimental results show that when the loading of N-GQDs is 7%of BiOX mass,the composite 7wt%N-GQDs/BiOX exhibits the highest photocatalytic activity in the process of photodegradation.Superactive radicals（·O₂^-）and holes（h⁺）are the main active groups by active capture experiments.Finally,in the cycle experiments,the light stability of 7wt%N-GQDs/BiOBr was better than 7wt%N-GQDs/BiOCl.（2）Synthesized and photocatalytic properties of ZnS/BiOBr/graphene oxide（ZnS/BiOBr/GO）composites.A facile and highly efficient ternary composite ZnS/BiOBr/GO with zinc vacancies was successfully synthesized by solvothermal method,the degradation of organic pollutants by composites with different amounts of GO was investigated under visible light.The crystal structure,morphology and optical properties of the synthesized catalysts were characterized by XRD,SEM,TEM,XPS,DRS and PL.The experimental results show that when the content of GO is 6 mg,the composite exhibits the highest photocatalytic activity and excellent light stability.Kinetics analyses were studing during the processes of photodegradation,it was found that it accorded with pseudo-first-order kinetic equation.·O₂^-and h⁺are the main active groups by active capture experiments.（3）Synthesized and photocatalytic properties of nitrogen-doped graphene quantum dot modified g-C₃N₄/BiOBr（BiOBr/g-C₃N₄/N-GQDs）composites.N-GQDs modified g-C₃N₄/BiOBr composite was synthesized by chemical co-precipitation,the degradation of organic pollutants by composites with different amounts of N-GQDs was investigated under visible light.The crystal structure,morphology and optical properties of the synthesized catalysts were characterized by XRD,SEM,XPS,DRS and PL.The experimental results show that when the content of N-GQDs（100 g/L）is 50?L,the composite exhibits excellent degradation ability to Rh B,its degradation efficiency reaches 94.57%.·O₂^-is the main active groups by active capture experiments.Finally,the degradation efficiency of the composite 200BCN-50 to Rh B remained above 80%after four cycles of experiments.