| Printing and dyeing wastewater has become one of the important sources of environment pollution. Methylene blue (MB) is one of the typical organic contaminants in the wastewater, is an important target for dyeing wastewater treatment. Photocatalytic oxidation is a novel method of the treatment for dyes. Researching and developmenting new photocatalytic materials and technology is very important.Based on the structural characteristics of peroxid-hydroxycarboxylic acid titanic complexes have multi-core and peroxo units, we used they as research subjects, researched the photocatalytic degradation character to deal with the actual printing and dyeing waste water of they, then the photocatalytic oxidation materials of nanocrystal titania were hydrothermally prepared using the synthetic complexes as precursor, The photocatalytic properties and structures of the synthetic nano materials were studied, wish to provide an new feasible method for the development of photocatalyzer.In this paper we used hydroxycarboxylic acid, ammonia, H2O2, Ti(OBu)4 and metal chloride as raw materials, Some peroxid-hydroxycarboxylic acid titanic complexes were designed and synthesized. The synthetic complexes were characterized by elemental analysis, IR, UV-Vis spectra, and single crystal X-ray diffraction method. The photocatalytic properties were deeply investigated. The photocatalytic oxidation materials of nanocrystal titania were hydrothermally prepared using the synthetic complexes as precursor, which were characterized by XRD and SEM as well. The photocatalytic properties of the synthetic nano materials were studied, and the influence factors were explored. The main conclusions of this thesis include the following four parts:1. Four Ti(Ⅳ) complexes constructed by the mixed ligands of peroxo and hydroxycarboxylic acid were synthesized: Li2(NH4)4[Ti2(O2)2(cit) (Hcit)]2·5H2O (1), Zn(NH4)4[Ti4(O2)4(Hcit)2(cit)2]·12H2O (2), Li2(NH4)4[Ti2(O2)2(Htart)(tart)]2·4H2O (3), Zn(NH4)4[Ti4(O2)4(Htart)2(tart)2]·11H2O (4).2. The hydrothermal method is more predominant in synthesis of nano materials. Fifteen nano materials of titanium dioxide were hydrothermally prepared under various conditions with different pH value. The experimental results showed that the hydrothermal method is more fit for the preparation of imperceptibility granule nano materials; all materials have main-phase nanocrystals titania with anatase structure, subandmini-phase in different pH value. The sub- and mini-phase have Ti(Ⅲ) or other compound semiconductor. It is not fit for Doping metal under hydrothermal conditions.3. Complexes 1 and 3 can effectively degrade MB under continuous light, showing the complexes exhibited stable photocatalytic performance. While complexes 2 and 4 possessed good adsorption property, and the adsorption quantity were effected by temperature and illumination.4. The pH value of the pre-solution is vital to the performance of the obtained nano materials. The materials prepared under the acidic condition showed excellent adsorption property, the materials coming from the neutral condition possessed good photocatalytic performance, while the photocatalytic performance of the materials synthesized in basic condition was ordinary. It is noteworthy that material 2 can rapidly degrade MB under sunlight. |
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