Preparation Of Fe₃O₄, SnO₂, SnO₂/Fe₃O₄ Nanoparticles And Research On Photocatalytic Property Of SnO₂ And SnO₂/Fe₃O₄

Nano SnO2 has small size effect, quantum size effect, surface effect and macroscopic quantum tunneling effect, which can also degrade organic matter under the irradiation of ultraviolet light. In a practical application, the recycling of nano photocatalytic materials is difficult. Nano Fe3O4 is widely used in various studies in the field of nano areas because of its magnetism. By coating a layer of SnO2 particles on the surface of Fe3O4, the recycling problem of nano photocatalytic materials SnO2 will be solved if the new particles have both magnetic and photocatalytic performance. Nanometer Fe3O4 and SnO2 powder were successfully synthesized by hydrothermal method. At the same time, Sn O2 was successfully coated on the surface of Fe3O4 by sol-gel method and hydrothermal method. XRD, TEM and photocatalytic tests were used to detect coated results. The article expounds in detail through the following three parts:(1)Preparation of Fe3O4 and SnO2 nanoparticles: Fe3O4 and SnO2 nanoparticles were prepared by hydrothermal method. Fe3O4 nanoparticles(8-15nm) were prepared at different temperatures of heat treatment, the effect of the dispersants on the dispersion was studied as a result of the preparation of Fe3O4 particles have serious phenomenon of reunion. In the process of preparation of tin oxide, about 5nm and 9nm SnO2 particles are obtained by changing the concentration of Na2SnO3.(2)Preparation of SnO2/Fe3O4 nanocomposite: SnO2/Fe3O4 composite nano particles were successfully achieved by using sol-gel method and sodium citrate modified the surface of ferroferric oxide. Different coated magnetic photocatalytic nano-particles were gained by changing the molar ratio of SnO2 and Fe3O4 response.(3) Photocatalytic performance test: Experiments had methyl orange for degradation solution, to degrade 100 ml of methyl orange(10mg/L) solution with 0.08 g, 0.16 g, 0.24 g and 0.32 g of SnO2. The results showed that 0.24 g SnO2 had the best degradation rate, and the degradation rate began to decrease slowly as the quantity of tin oxide increasing. In the photocatalytic degradation experiment of SnO2/Fe3O4, the amount of compound particles 0.24 g for the degradation of methyl orange solution rate is the highest. Finally, the paper studied the effect of the darkroom disposal and recycling times. The experimental results show that the recovery rate is higher and the recycling times has slight effect on photocatalytic effect, which suggested it still has a certain significance within a certain number of recycling times.