Preparation And Photocataiytic Performances Of Several Composite Nanofibers Based On Electrospinning

In the21st century, people are faced with more environmental problems. Amongthe environmental issues, water pollution is a very serious problem. In the pollutedwater, there are some difficult degradation products of organic pollutants, and theseorganic pollutants on the environment have a great harm. So, many researchers arelooking for a new way to solve this problem. Now, after a lot of researches it is foundthat the presence of catalytic technology is applicable for a wide range of mildreaction conditions, simple reaction equipment, easily operating and so on. So thistechnology has played a very important role in coping with the challenges ofincreasing environmental problems.At present, the usefully applied photocatalysts to degrade organic pollutants inwater are mainly metal oxide which is a n-type semiconductor material or acidsubstance, such as TiO2, CdS, SnO2, ZnFe2O4and WO3. Among these photocatalysts,TiO2is the most prominent one, because TiO2has some special advantages, such asits chemical stability, high activity, low cost and non-toxic. Above all, TiO2isconsidered to have the most practical prospect.With the development of nanotechnology, electrospinning technique is aneffective technology for preparing nanofibers, which is playing a big role in the areas of biomedical materials, filtration, protection, catalysis, energy, photoelectricity, foodand cosmetics. In this paper, a combination of sol-gel method, reflux method andhydrothermal method, mainly based on electrospinning technique, is used to preparedifferent kinds of photocatalytic materials, such as the composite nanofiber materialsof TiO2/Al2O3, TiO2/Al2O3/ZnS and TiO2/Ag. By studying the photocatalyticproperties of these composite nanofibers, more functional nanomaterials will beachieved.First of all, we combine the sol-gel and electrospinning method to obtainTiO2/Al2O3composite nanofiber materials. Then with the help of hydrothermalmethod, ZnS nanoparticles have been successfully loaded on the surface ofTiO2/Al2O3composite nanofibers. Finally we get the nanofiber composite materialswith the TiO2/Al2O3/ZnS heterostructure. By controlling the concentration of rawmaterials, we can achieve different loadings of ZnS nano-particles. We also researchtheir associated photocatalytic properties by the degradation of Rhodamine Bdye.Next, we use the same way of combining the sol-gel and electrospinningmethod to get the precursor fiber materials of TiO2.By calcinating the precursor, thepure anatase TiO2nanofibers are achieved. After that, we take the method ofcirculation reflux to load silver nanoparticles to the surface of nanofibers, with thehope of further improving of photocatalytic performance. By the means of controllingthe concentrations of silver-ammonia solution, we can acquire different contents ofAg nanoparticles loaded on surface of TiO2nanofibers.At last,we discuss the differences between the pure TiO2nanofibers and the TiO2nanofibers loading different contents of Ag nanoparticles. Through the degradation ofRhodamine B dye, we find that the photocatalytic performance of TiO2nanofibersloading Ag composites is superior to pure TiO2nanofibers, and the right amount of Agnanoparticles has the best photocatalytic property.