| ABSTRACTEnvironmental pollution and energy crisis are the common problem in all of the countries. Effective utilization of solar energy to solve pollution problems has become of great interest in the world. The photocatalytic technology, which is a kind of advanced oxidation technology, has the advantages of high efficiency, fast, green, utilization of solar energy. And TiO2 photocatalyst is the most important environmental material.The research of metal semiconductor photocatalystic materials has been lasted for many years. It has been pointed out that the property of photocatalyst is affected by factors-crystal form, crystal size, temperature, quality of loaded mental ion, coupled semiconductor materials and so on. Meanwhile, morphology is also a important factor, which will affect the quality of surface absorption, absorbed ways, light path, et al. The synthesis of hollow sphere structure is a part of morphology research. The traditional synthesized method of hollow sphere is to use varies of templates which is cheap and removed easily. Mental ion semiconductor particulars absorb onto the surface of templates firstly, then the templates removed by high temperature or solvent. In our research, pollens have been employed to synthesize copper loaded TiO2 hollow spheres photocatalysts. Biotemplates has so many shapes (griddle shape, reseau, sphere, cylinder, et al.) and advantages such as small size, easy control, cheap, green, no-pollution and so on.Copper-loaded titania hollow microspheres were synthesized using the pollen grains as a natural biotemplate via an improved sol-gel method and a succedent calcinations process. In the synthesized process, the water was provided by two processes, esterification of normal butanol and acetic acid, as well as Ti(OR)3(OH) condensation reaction, unlike the conventional sol-gel procedure of adding water directly. This synthesized method can obviously avoid the rapid condensation reactive speed and gel reunion. In the experiment, the temperature and pH changes regularly. Temperature doesn't reach the maximum value until 300min reaction; meanwhile, reaction equilibrium will also be attained.A series of photocatalysts has been synthesized through the distinct processes-different molar ratio, pH, and quality of copper loaded. The best synthesized condition is Ti (OC4H9)4:n-C4H9OH:CH3COOH=1:4:4, pH=3,2 wt.% copper loaded quality. Knowing from SEM, XRD, BET equipment analysis, average diameter of hollow spheres is 20μm and thickness of cell is 0.6μm. The crystal form of semiconductor material is changed with the temperature. When the calcination temperature is at 500℃, the samples crystal forms are anatase, as the main crystal phase, coupled with rutile. BET values are ranging from 141.80m2/g to 172.51m2/g, compared with values of particular and p-25 photocatalyst,51.85 m2/g and 50 m2/g, respectively. The hollow sphere photocatalysts have higher BET surface area so that it will, have stronger absorption ability.The hollow sphere photocatalyst has exhibited a high photocatalytic activity when it is employed to degrade chlortetracycline hydrochloride (CTC) solution. After 120min irradiation, the maximum degradation ratio of CTC is 99.66%, COD removal efficiency could reach up to 95%, as well. Meanwhile, chemical and biologic properties of waster water will be improved, when the value of BOD5/COD> 0.3. The best technological conditions of degradation process are as follow:dosage of catalysts is 1.2g/L, initial concentration of CTC is 50mg/L, pH=2. When the concentration of H2O2, added into the reaction system, exceeds 300mg/L, the reaction time will be cut down in half. During the photocatalytic processes, chemical mechanism on degradation of CTC involves series of photooxidation processes and subsequent chemical reactions. Intermediate products of Chlortetracycline included a variety of bicyclic, tricyclic compounds. Polycyclic compounds will be opened up, and then aldehydes, quinones, enolase and other small molecular compounds were produced. Ultimately, CO2, H2O, NH4+ and other inorganic products were investigated.We can come to the conclusion that the pollen has played three important roles in the process. Firstly, it serves as a hard template to form the morphology of the products. Secondly, the abundant functional groups on the surface of pollen gains are active sites to absorb the reactants. And the groups are also critical factor to control the first-step encapsulation process. Thirdly, the bimolecular on the cell walls exert an influence on restraining the growth of nanoparticles.In summary, Cu/TiO2 photocatalysts with good three dimensional morphology and crystal characteristics have been synthesized successfully, which have better activity and utilization prospect than p-25. The analysis of degradation process conduction of CTC antibiotic waster water, as well as degradation product can be helpful to further research. However, there is a lot of work to be improved in order to strive for excellence.
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