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Recent years, with the over-exploitation of resources utilization and increasingly serious environmental pollution, human living environment has been seriously damaged, the environmental issue has become one of the main issues of concern to the world today. Photocatalytic semiconductor photocatalyst by photoexcitation, the formation of photo-generated electrons and holes from the valence band and the conduction band of the semiconductor position, respectively, the photo-generated electrons and holes generated by the light of subsequent participation in pollutants degradation reactions. Compared with other environmental control technology, the main advantage is the Photocatalytic Degradation: without secondary treatment, the degradation of organic pollutants in water and air H 2 O, CO 2 and other small molecules and inorganic pollutants mineralization; can use sunlight to stimulate the participation of photocatalyst in photocatalytic reaction without the need for other sources of energy; photocatalyst can be self-generated and can recycling reuse. Ideal photocatalyst should be good stability, low cost, non-toxic, highly reactive and can fully absorb sunlight. Photocatalyst However, current research and applications (such as the TiO 2 ), there is a narrow range of light response, the photo-generated electron-hole recombination rate, resulting in low catalytic efficiency, so how to expand the photocatalyst response range, reduce the recombination rate of photo-generated electrons and holes, and improve the efficiency of photocatalytic the photocatalyst today research direction. TiO 2 is the study and application of more light catalyst with high stability, strong light catalytic ability, non-toxic and non-polluting, and other prominent advantages. Since the wide band gap of TiO 2 (for 3.2eV), corresponding lightwave absorption as a wavelength of 387.5nm light absorption only in the ultraviolet region, and its absorption spectrum was only a small part of the solar spectrum, In addition, the higher photo-generated electron-hole recombination rate, leading to TiO 2 quantum efficiency can not take full advantage of the sunlight; ZnO has good optoelectronic properties, major studies have focused on the luminescence properties and piezoelectric properties, and the study of its photocatalytic properties are relatively small, with the TiO 2 compared to the semiconducting properties of ZnO more excellent, but it is also a wide band gap semiconductor material (3.37 eV), sunlight low utilization rate. α-Fe 2 O 3 band gap of 1.9-2.2eV, the absorption spectrum of the solar spectrum matched well, the use of solar energy can be better, but the light the absorption efficiency is low. Given that this has a wider band gap TiO 2 , ZnO and α-Fe than the narrow band gap 2 O 3 the advantages and disadvantages of these two types of materials, if they can α-Fe 2 O 3 of TiO 2 , ZnO made of core-shell structure of the composite material, through a composite of a semiconductor, expandable material the light absorption range, to improve the rate of charge separation and the light absorption rate, thereby improving the catalytic efficiency of the photocatalyst. This article was prepared by hydrothermal nano-α-Fe 2 O 3 the ZnO, alpha-Fe 2 O 3 / TiO 2 α-Fe 2 O 3 / ZnO core-shell composite structure of nanomaterials, and their structural, physical, chemical and photocatalytic properties of the in-depth study. The main content of the paper and the results are as follows: 1) first chapter introduces the research background of photocatalytic photocatalytic reaction types and principles, materials preparation, material modification and photocatalytic materials. Summary of the analysis on the basis of progress in the field of photocatalytic today, to this thesis research plans and targets. 2), the second chapter we use Hydrothermal Synthesis of nanocrystals of different morphologies of α-Fe 2 O 3 , and by means of XRD, TEM, SEM test on its characterization, their photocatalytic nature. The nano particles have a rod (80-200nm), hedgehog-like nanorods (rods (600nm), as well as the growth of an α-Fe on the FTO glass 2 O 3 length of about 200nm, a rod width 40nm), the material is a single phase, high purity, high crystallinity. 3), the third chapter prepared α-Fe 2 O 3 / TiO 2 core-shell structure, by means of XRD, TEM, test structure characterization, and study the impact of different mass ratios, the catalyst concentration, reactant concentration, and its catalytic efficiency. 4), Chapter Hydrothermal Synthesis of ZnO nanorods grown on FTO glass with a certain orientation ZnO nanorods were characterized by XRD, TEM and SEM test means, analysis of the ZnO crystal phase and morphology. Simple study the photocatalytic properties of ZnO. 5), Chapter V of the use of the Hydrothermal Preparation alpha-Fe 2 O 3 / ZnO composite nanomaterials, XRD, TEM and other means of testing, analysis of the composite of α- Fe 2 O 3 / ZnO crystal phase and morphology. The impact of different mass ratios, the catalyst concentration, concentration of reactants on the catalytic efficiency of the photocatalytic material in the composite. 6), the last chapter of the thesis work were summarized and future work some of the ideas and suggestions. Photocatalyst through the research of the system described above, to find the appropriate preparation conditions, to determine the appropriate mass ratio to prepare a composite nano-material having a higher photocatalytic performance, while the system studied the effects of various factors of the light-catalyzed reaction rate, Explore the composite photocatalytic mechanism and ways to improve the catalytic performance.
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