| Because of its simple operation, mild reaction conditions, easy control, without secondary pollution, has good effect to treatment the wastewater containing refractory organic pollutants, photocatalytic oxidation technology has attracted wide attention of the scholars at home and abroad. It has been applied to a certain extent in the field including sterilization, disinfection, air purification, sewage treatment and hydrophilic materials, etc. Photocatalytic oxidation technology is one of the technologys to use photocatalytic materials degradating organic pollutants under the condition of light irradiation, that can degradate the pollution to carbon dioxide, water and other small molecules, but it is difficult to develop the photocatalytic materials that had durable photocatalytic performance, high catalytic efficiency and recyclable reuse,this is always a difficult problem we faced to develop the technology in the field of photocatalysis oxidation.（Nickel oxide, Titanium dioxide, Zinc Oxide, etc.）Nano-metal oxide are considered to be the most potential promotion metal oxide catalyst, which is chemically stable, non-toxic, easyly preparation, the preparation low cost, good acid and alkali resistance, good catalytic performance.But because of the particles of nano-metal oxide is small, the quality is light, not easily sedimentated in the practical application, it was difficult to make it separation in the solid-liquid system, these had the limitation that large amount of catalyst had lost when recycled, the rate of duplication utilization was low. There had an effective way to solve the problem that catalyst was difficult to separation and recycled, to load nano-metal oxide catalytic on the carrier that had larger surface. Combined the metal oxide particles with carrier has larger specific surface area, not only solve the problem that nano-metal oxide particles separation and recovery difficultly in the water, at the same time has good adsorption properties for organic pollutants because of the carrier has larger specific surface area, to adsorb the organic pollutants on the surface of the carrier and metal oxide nanoparticles easyly, also increased contact time and chance of the metal oxide particles and organic pollutant molecular, thus improving the photocatalytic properties of composite materials. In addition, to introduced the magnetic material into the photocatalytic composite material, the sample can be recovered and recycled by magnetic separation after the photocatalyticdegradation of pollutants, that can effectively avoiding the loss and waste of photocatalytic composite material, realized the reuse of photocatalytic materials and saved resources.In this paper, by employing the graphene（GNs） as the carrier, we synthesized the GNs/Fe3O4/Ni O magnetic nanocomposites, GNs/Fe3O4/Ti O2 magnetic nanocomposites and GNs/Fe3O4/Zn O magnetic nanocomposites by emulsion intercalation hydrolysis method, ultrasonic assisted synthesis method and hydrothermal synthesis method, successfully loaded Fe3O4 magnetic nanoparticles and metal oxide photocatalytic materials（Ni O, Ti O2 and Zn O） on the surface of graphene, respectively. The sample of GNs/Fe3O4/Ni O,GNs/Fe3O4/Ti O2 and GNs/Fe3O4/Zn O nanocomposites photocatalyst with different content of Ni O, Ti O2, Zn O be synthesized successfully. The photocatalytic properties were tested by using p-nitrophenol and Rhodamine B as the target pollutants, also tested the influence of the content of Ni O, Ti O2, Zn O to the catalytic performance of composites.The samples were characterized by Fourier transform infrared spectroscopy（FTIR）, X-ray diffraction（XRD）, Scanning electron microscopy（SEM）, Transmission electron microscopy（TEM）, Energy dispersive X rayspectrometer（EDX）, Thermal gravimetric analysis（TG） and Vibrating sample magnetometer（VSM）, and tested the adsorption performance and photocatalytic properties of catalytic composites. When the content of metal oxide particles of composite materials was 75%, the photocatalytic degradation of composite materials to p-nitrophenol and Rhodamine B rate were more than 90%. The results showed that the nanocomposites had good effect, with high stability, high catalytic efficiency, recycling and reusing by magnetic separation. In summary, composite materials have the advantages of preparation simply, the catalytic performance were good, has great potential in terms of scale application in sewage treatment. |
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