| In recent years, with the continuous development of nano-technology, Nano-composite materials have become a hot research topics in the field of materials science. Graphene oxide are low cost, raw materials readily available and have good physical and chemical properties, such as high specific surface energy, good hydrophilicity, good mechanical properties and good dispersibility in water and in organic solvents. As good composite fillers, Graphene oxide own broad and far-reaching application background, having been an important research of nano-composite materials in recent years.There are many remaining dyes in the discharge of wastewater of textile, leather, paper, printing and cosmetics industries. These dyes, which have caused great harm to the environment, are not easily removed because of complex and stability aromatic structures. Therefore, it is very essential to treat these dyes wastewater. Physical and chemical methods are the most commonly used methods to remove dyes wastewater. Adsorption is an economical and effective way in these methods, and so it is essential to choose a good adsorbent. All the time, carbon materials are used as adsorbents in wastewater due to its special surface properties. As a new member of carbon nano-materials family, Graphene oxide which have a very large specific surface area will be a very good adsorbent. Studies have shown that factionalized graphene have a very good effect on the adsorption of Pb(â…¡) and Cd(â…¡). There has been little research on the adsorption of graphene oxide for organic compounds. My dissertation is focused on the preparation of nano-composites and treatment these dyes wastewater. Now, some new result are obtained from our experiments.1. First, we preparer graphite oxide by a modified Hummers method. And then, after ultrasonic treatment, we access dispersed Graphene Oxide. The structural properties are characterized by SEM, TEM, XRD and FTIR. The results of XRD and FTIR show that spacing of graphite oxide become large and the surface contain a large amount of functional groups including carboxyl, hydroxyl, epoxy and so on. The graphite oxide with these functional groups is hydrophilic. The study of the oxidation process shows that the ratio of graphite and potassium permanganate ratio, the reaction time under low temperature process have influence on temperature on the structure and properties of products. The hyperthermal reaction in high temperature process decompound the oxygen-containing functional groups and impact the structure of products.2. G/silica/Fe3O4nano-composites are prepared with solution mixed method. The structural properties are characterized by SEM, TEM, XRD, FTIR and magnetic lines. The new materials have produced will be used to adsorb dye waste water containing methyl violet and malachite green. Some impact factors have been discussed through optimizing experiment conditions, such as initial concentration of dyes, the concentration of adsorbent, pH value and absorption time. The result indicates that adsorption of adsorbent for actual samples value up to85%or more, and the adsorption rates are still in80%after five cycles.3. G/Fe3O4nano-composites are prepared with one step synthesis method. The G/Fe3O4nano-composites not only have good adsorption capability and also magnetic recycle. The structural properties are characterized by SEM, TEM, XRD, FTER. and magnetic lines. The new materials have produced will be used to adsorb polycyclic aromatic hydrocarbons. Some impact factors have been discussed through optimizing experiment conditions, such as initial concentration of dyes, the concentration of adsorbent, pH value and absorption time. And adsorption mechanism are also studied. The result indicates that adsorption of adsorbent for polycyclic aromatic hydrocarbons are good.4. G/TiO2/CoFe2O4three-element nano-composites are prepared with one step one step hydrothermal synthesis method. The structural properties are characterized by SEM, TEM, XRD, FTIR and magnetic lines. The photocatalytic activity of the G/TiO2/CoFe2O4was investigated using ultraviolet-visible absorbance by following the photocatalytic oxidation decomposition of a model pollutant dye solution, methylene blue (MB) in a photochemical reactor. Some impact factors have been discussed through optimizing experiment conditions, such as initial concentration of MB, the usage of catalyst, pH value, irradiation time, and also the different photodegradation systems. The result indicates that G/TiO2/CoFe2O4three-element nano-composites have more superior photocatalytic property and avoiding collection difficulties, comparing with the traditional semiconductor materials TiO2. |
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