| 摘要: | 研究期間：10108~10207;How to treat industrial wastewater is an important issue in the present day. In order to reduce environmental pollution, many kinds of technologies for treating various wastewaters have been developed. However, the developed technologies are still deficient for completely solving all problems up to now. Frequently, photocatalyst is used to increase removal efficiencies of contaminants in the recent years. This way could reduce the addition of chemical reagent to wastewater. The photocatalysts such as titanium dioxide (TiO2), and zinc oxide (ZnO) are generally applied to examine the results of contaminant removal ratios. Because titanium dioxide possesses the higher photostability and the better photodegradation efficiencies for contaminants, it is most commonly selected as photocatalysts. Photoluminese exited level of zinc oxide is similar to that of titanium dioxide. However, zinc oxide possesses a relatively wider range of absorbed wavelength, leading to greater photon adsorbed. In addition, zinc oxide in base solution to photodegrade dye can produces the higher efficiency. Also, zinc oxide has the advantages of economy, low toxicity, and low interference. Moreover, photocatalyst, zinc oxide, to photodegrade organic compounds needs to be studied further. Synthesis method of photocatalyst includes laser ablation, hydrothermal, sol-gel and spray pyrolysis. Some of disadvantages for these methods need to be improved. In this study, the dehydration condensation reaction and hydrothermal method was used to produce the photocatalyst of zinc oxide. Polysaccharide (e.g. cellulose and chitosan) was used as the reactant. The project of photodegrading organic compounds will be finished for three years. First, the affinity of natural polysaccharides for zinc was studied to be a reference of following derivatization study. Then, various graft copolymerization and gelation process will be applied to increase complex ability of the derivative between polysaccharide and zinc. The key point is pyrolysis of high temperature calcinations to synthesize zinc oxide based on the ligand theory. The surface characteristics of derivative and oxide zinc are analyzed using TEM, SEM, NMR and X-ray. The photodegradation efficiency of oxide zinc obtained from the proposed method is compared with that from the traditional method. Finally, the difference in photodegradation efficiency between the zinc oxide synthesized via polysaccharide and its derivative and titanium dioxide are also discussed. |
