| 17α-ethynyl-estradiol (EE2) is the most potent endocrine disrupting compounds (EDCs). It is used as sexy hormone drugs, and exists in water widely. Even in low concentration, EE2 can lead to bad effects for organisms. It is urgent to explore new methods and new materials to remove EE2.TiO2 is widely used in the degradation of organic pollution, since it is nontoxic, chemically stable, and relatively inexpensive. However, the rapid recombination of photogenerated electron-hole pairs and low adsorption capacity for organic contaminants decreased the photocatalytic activity of TiO2.Combining TiO2 with graphene can reduce the electron-hole recombination rates and improve the adsorption capacity of the organic contaminants, thus enhance the photocatalytic performance.In this thesis, we combining TiO2 with graphene by utilizing the high adsorption ability and the efficient electron transfer ability of graphene. TiO2/reduced graphene oxide nanocomposites (TiO2-RGO) and surface fluorinated TiO2/reduced graphene oxide nanocomposites (FTG) were synthesized, and they were characterized by TEM, XRD, Raman and XPS. The adsorption ability and photocatalytic activity of the nanocomposites was evaluated by degradation of EE2.First, TiO2-RGO were prepared using tetrabutyl titanate (TBT) and graphene oxide (GO) as the starting materials via hydrothermal reaction. Adsorption ability and photoca(?)tic activity of TiO2-RGO by degradation of EE2 was evaluated. The results showed that, the optimal conditions included that the volume ratio of water and ethanol was 1:1, the mass ratio of RGO was 8%, the catalysts dosage was 0.3g/L and the initial pH value of EE2 was 6.0. Under the optimal conditions, the adsorption removal ratios of EE2 over TiO2-RGO and commercial TiO2 (P25) were 41.7% and 5.8%, the photocatalytic degradation removal ratio over the same catalysts were 58% and 69.8%, and the total removal ratio over the same catalysts were 99.7% and 75.6%. It was indicated that TiO2-RGO exhibited much higher removal ability for EE2 compared to P25. The introduction of GO in the TiO2 can enhance the adsorption ability for EE2, which can play a synergistic role for photocatalytic degradation, thus the photocatalytic performance of TiO2-RGO enhanced.Second, FTG were synthesized using TBT, GO and HF as the starting materials by a facile one-step hydrothermal method. In the prepared photocatalysts, the anatase TiO2 nanoparticles were size of 20-30 nm, which were larger than the TiO2 nanoparticles in the aforementioned TiO2-RGO. This was because that the F- enhanced the crystallization of the TiO2 anatase phase by anchoring on the surface of TiO2 particles. The adsorption ability and photocatalytic activity of FTG was evaluated by degradation of EE2. The results showed that, the optimal conditions included that molar ratio of TBT to HF was 1:1.5, the mass ratio of RGO was 4%, the catalysts dosage was 0.3g/L and the initial pH value of EE2 was 6.0. Under the optimal conditions, the adsorption removal ratios of EE2 over FTG was 33%, the photocatalytic degradation removal ratio was 66.7%, and the total removal ratio was 99.7%. The results also indicated that FTG exhibited efficient removal ability for EE2 compared to P25. Due to the enhanced adsorption ability by RGO and improved crystallization of anatase TiO2 by F", a high photocatalytic activity was achieved by the synergetic enhancement effect of RGO and F.At last, we compared the performance of TiO2-RGO and FTG The two nanocompotites both exhibited an excellent adsorption capability and much higher efficient removal ability for EE2 compared to P25. In order to save the economic cost and improve the catalysis efficiency, FTG is more suitable. |
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