Research On Synthesis Mechanism And Properties Of TiO₂-Ag-Fe₂O₃ New Nano Composite Particles By Laser

Nano-TiO2 which is used as photocatalyst has a broad prospect of application in catalytic degradation due to its high photocatalytic activity, non-toxicity, stable antibiotic property, wide application and low cost. However, TiO2 has narrow light response range and is difficult to work in dark. In recent years, people try to improve its properties by depositing precious metals, compositing semiconductor and doping ion. Silver is precious metal and nano-Ag particles has no requirement for illumination as antibacterial agent because of its large specific surface area and high activity. At the same time, nano-Ag retains good properties such as good conductivity, strong sterilization ability and low consumption. On one hand, Fe2O3 can improve the photocatalytic activity of TiO2 as semiconductor; On the other hand, Fe2O3 can realize the separation and recovery of nano-TiO2 composite particles as magnetic materials. How to composite Ag, Fe2O3 and TiO2 into multiphase nano-materials scientifically, exerting the advantages of every component, synthesizing new TiO2-Ag-Fe2O3 composite nano-particles which has good catalytic degradation of pollutants, antibacterial and magnetic properties has important scientific value and wide application value.Based on designing the multiphase composition proportion, controling composite structure and expanding function, this paper use pulse laser vapor evaporation-liquid collection to prepare TiO2@Ag core-shell nanoparticles and TiO2-Ag-Fe2O3 mixed-phase nanoparticles. The morphology, particle size, organizational structure, magnetism, photocatalytic and antibacterial properties of nano-TiO2 composite particles are studied by using special instruments, such as TEM, XRD, FT-IR and VSM.The results show that the the TiO2@Ag core-shell nanoparticles have spherical structure and the particles size grow bigger with longer duration. The nano-particle size distribute between 15nm-35nm with covering 2h. The nano-particle size distribute between 30nm-50nm with covering 4h. TiO2-Ag-Fe2O3 mixed-phase nanoparticles has spherical structure and particles size distribute mainly between 10nm-25nm. Focusing on synthesizing TiO2-Ag-Fe2O3 nanoparticles, the transmittance of FT-IR has red shift, which made it adjustable optically. Compositing Fe2O3 can contribute to magnetic recycling and compositing Ag can improve the antibacterial properties; The methyl orange degradation rate of TiO2-Ag-Fe2O3 three-phase composite nanoparticles reaches 55% and the composite nanoparticles can resist to E.coli to some degree.