| Due to its highly conjugated structure and unique properties, porphyrins have been extensively used as excellent photosensitizer in dyes-sensitized solar cells and photocatalytic degradation of organic wastewater through modified Titanium dioxide (TiO2). In treatment of organic waste water, TiO2 can produce strong oxidizing hydroxyl radical (·OH) under ultraviolet irradiation, which almost oxidize lots of organic pollutants into CO2, H2O and other small molecules. However, the optical absorption of TiO2 is in the UV region, which limits the use of solar spectrum in its practical application. As the most promising sensitizer, porphyrin loaded on the surface of TiO2, can expand the response spectrum of TiO2 to visible light and lay a good foundation for making use of sunlight. It is well known that it could control the interaction with the TiO2 surface and the porphyrins and also enhance the visible light sensibility of the TiO2 by associating with different substituents and functional groups.Hence, six porphyrins containing different peripheral substituents:5-(4-hydroxyl)phenyl-10,15,20-tri-phenylporphyrin (H2MHTPP), 5,15-di-(4-hydroxyl)phenyl-10,20-di-phenyl porphyrin(H2DHTPP); 5-[(4-acetateethyl)methoxy]phenyl-10,15,20-tri-phenylporphyrin (H2METPP), 5,15-di-[(4-acetateethyl)methoxy]phenyl-10,20-di-phenylporphyrin (H2DETPP); 5-[(4-carboxyl)methoxy]phenyl-10,15,20-tri-phenylporphyrin (H2MCTPP); 5,15-di-[(4-carboxyl)methoxy]phenyl-10,20-di-phenylporphyrin (H2DCTPP) were successfully synthesized and characterized in this thesis. Their corresponding Cu(Ⅱ),Ni(Ⅱ),Co(Ⅱ),Zn(Ⅱ),Mn(Ⅲ) metalloporphyrins were obtained through the reaction of metal acetate and free porphyrins.The TiO2-based photocatalysts were prepared and characterized by UV-vis absorption spectrum, Infrared spectroscopy (IR), Transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). It could be found that porphyrins were loaded on the surface of TiO2 and there is a weak interaction between porphyrin and the surface of TiO2. The porphyrins on the surface of TiO2 were able to enhance the ultraviolet and visible light sensibility of the TiO2 associated with different substituents. In photochemical reaction apparatus, the photacatalysis activity of the catalysts was evaluated by measuring degradation efficiency of 4-nitrophenol (4-NP) under different light source, such as mercury lamp, metal halide lamp and xenon lamp. The process of all photocatalytic reaction conformed to the kinetics of first order reaction. Then the reaction kinetics and reaction rate were calculated in this work. It was found that reaction of anatase TiO2 samples impregnated with metal mono-carboxylporphyrin were the fastest among all photocatalysts by carrying out the photodegradation of 4-nitrophenol (4-NP) in aqueous suspension. Based on various factors, the photocatalytic efficiency of Cu(MCTPP)-TiO2 photocatalysts were the highest. Meanwhile, the degradation efficiency of photocatalysts showed similar results as above. In order to evaluate stability of photocatalysts which is very essential for the practical application, the long time using of the Cu(MCTPP)-TiO2 photocatalysis for 4-NP degradation was carried out and it was confirmed that these copper porphyrins supported onto TiO2 showed good stability under irradiation conditions.When metal mono-carboxylporphyrins were used in thionyl chloride batteries as catalysts, the results showed that Cu(MCTPP)and Zn(MCTPP) had excellent performance in catalyzing Li/SOCl2 batteries, such as:extending electric discharge time, improving the average voltage battery and expanding battery capacity. |
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