Preparation And Properties Of Bismuth Tungstate, Tin Oxide And Zinc Oxide Micro-nano Materials

Micro-nano materials because of its unique physical and chemical properties in catalysis,sensing,optoelectronics has a wide range of applications,Therefore,preparation of novel metal oxide nanomaterials,controlling their morphology,size and dimension,and studying their growth mechanisms have become the hot topics in this field.In this dissertation,novel micro-nano materials were prepared by using micro-nano materials of semiconductor metal oxides(ZnO and SnO2)and discussed its possible formation mechanism.The application of these four kinds of micro-nano materials as photocatalysts to degrade organic pollutants was studied.(1)The AgVO3/Bi2WO6 heterojunction composite was doped with different contents of AgVO3 during preparation,the photocatalytic activity of Ag-BW was evaluated by photodegradation of Methyl orange(MO)under simulated visible light.The results showed that the photocatalytic activity of 0.2Ag-BW under visible light for degradation of MO was up to 90.35%within 120 min,which was much higher than that of other doping and pure compound.It was significantly found that the introduction of AgVO3,which suppressed the recombination of photogenerated electron-hole pairs on the interface of Bi2WO6,leading to enhanced photocatalytic activity.(2)The novel hierarchical flower-like SnO2(HFL-SnO2)nanostructures with the diameter of about 500nm,which are composed of regular-shaped nanosheets.Based on the nucleation and self-assembly process,possible formation process of the new hierarchical flower-like nanostructures can be presented.Moreover,the obtained HFL-SnO2 nanostructures exhibit higher photocatalytic activity towards the degradation of RhB under visible-light irradiation,up to 90.34%within 120 min.In short,this study provides an effective way to control and design the shape of SnO2.(3)Synthesis of SnO2 doped carbon nanotubes is formed of a composite material consisting of a curved sheet-like layered flower ?-CNTs/SnO2 nanostructures by hydrothermal method.The ?-CNTs/SnO2 composite was doped with a-CNTs during preparation,the photocatalytic activity of ?-CNTs/SnO2 was evaluated by photodegradation of Rhodamine B(RhB)under simulated visible light.The results showed that the photocatalytic activity of ?-CNTs/SnO2 for degradation of RhB was up to 90.32%within 120 min.(4)A novel flower-like GN/ZnO nanostructure composed of a curved cone of graphene doped with ZnO was synthesized by hydrothermal method.the photocatalytic activity of GN/ZnO was evaluated by photodegradation of Rhodamine B(RhB)under simulated visible light.The results showed that the photocatalytic activity of GN/ZnO for degradation of RhB was up to 90%within 50 min.