| Dye is a necessity for textile printing and dyeing industry, it’s not easy to fall off from fibre. Most of dyes are materials with the characteristics of strong toxicity, difficulty to biochemical degradation and poor biodegradability. Dyes wastewater can bring a series of environmental problems and cause different degrees of damages to water, soil, plants, human and so on when they stay in the soil or flow into waters. Therefore, the treatment of how to solve the problem of dye wastewater has been widely researched and paid much attention. Photocatalytic oxidation technology is a new pollutant treatment technology, in the role of light and catalyst, toxic organic contaminants can be degraded into non-toxic substances such as dioxide carbon, water, inorganic salt. Because of the mild reaction condition and no secondary pollution, the technology has a broad application prospect in the field of wastewater treatment. Titanium dioxide (TiO2) has been considered as the most widely used semiconductor oxide photocatalyst owing to its low cost, non-toxicity. mild reaction conditions and excellent chemical stability. However, the adsorption ability of TiO2 is very low. it can only have a response to near-UV light and difficult to be reused, which limit the application of photocatalyst. Based on the large specific area and excellent mobility of charge carriers of graphene and magnetic response characteristics of Fe3O4 we prepared magnetic grap hene-Fe3O4-TiO2 to improve the ability of adsorption of TiO2 and recycle the composite with permanent magnet. On this basis, we studied the behavior of the composite photocatalytic degradation of organic wastewater. This paper includes the following contents:(1) Firstly, graphene oxide (GO) was obtained using Hummers method, then GO was reduced into graphene (RGO) under the action of reducing agent. On this basis, we successfully synthesized Graphene-TiO2 (RGO-TiO2) composite photocatalyst by hydrothermal method. The composite was characterized by FT-IR, XRD, UV-vis/DRS, SEM and TGA. The structure, morphology, ther mo stability and light response range were analysised through these methods.(2) The adsorption capacity and photocatalytic performance of Graphene/TiO2 was tested using Rhodamine B (RhB). The influence of experimental conditions such as different catalysts, raw RGO-TiO2 quality ratio, pH value, initial concentration and catalyst dosage was studied under the irradiation of xenon lamp and the recycling performance of Graphene-TiO2 was investigated in this work. The results show that under optimal conditions for preparing and degradation, RGO-TiO2 composite photocatalyst light adsorption and degradation efficiency of rhodamine B is better than pure TiO2 samples. Photocatalytic Degradation of reaction the pseudo-first-order reaction kinetics. In addition, the composite photocatalyst has a better recyclability.(3) First, we prepared magnetic response Fe3O4-TiO2 particles with acid-sol method and on this basis, the composite was loaded onto graphene using hydrothermal method. The magnetic RGO-Fe3O4-TiO2 composite was characterized by FT-IR, XRD, TEM, UV-vis/DRS, Ms and TGA. Structure, morphology, thermostability, magnetism and light response range were analysised through these methods.(4) The adsorption capacity and photocatalytic performance of RGO-Fe3O4-TiO2 was tested using Methylene Blue (MB). The influence of experimental conditions such as different catalysts, initial concentration, pH value and catalyst dosage was studied under the irradiation of xenon lamp and the recycling performance of magnetic RGO-Fe3O4-TiO2 composite was investigated in this work. The results show that under optimal conditions for preparing and degradation, the adsorption and degradation efficiency of RGO-Fe304-TiO2 composite light is better than pure TiO2 samples. In addition, the composite has a better recyc lability. |
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