Preparation And Photocatalytic Activity Of TiO₂Nanofibers By Electrospinning

With serious enviromental pollution concern, environment protection gradually has become the peoplecared focus. Titania as a photocatalytic material, with potential value in enviroment purification, has been the focuses to researchers. How to implement high-efficiency catalysis is one of the hotspots and difficult problems of titania. In this thesis, TiO2/ZnO and TiO2/Fe2O3nanofibers were successfully prepared by sol-gel and electrospinning technique. The visible-light photocatalytic activity to degrade rhodamine B under visible-light irradiation was studied, through adjusting some factors, such as temperature, concentration, doping amounts, etc. Following are the main content of this thesis:1. The impact on electrospinning performance of the electrospinning conditions was discussed, such as the concentration of PVP and acetic acid, the voltage, and the electrode spacing. Taking SEM as the characterization, the optimum electrospinning conditions was:solution concentration PVP:Ti(OiPr)4:ethanol:acetic acid=3.2%:32%:42.3%:22.5%, voltage of 15KV, electrode spacing of15cm.2. Under the optimum electrospinning conditions, precursor fibers were prepared by electrospinning technique, and fabricated TiO2/ZnO and TiO2/Fe2O3nanofibers by calcinations at high temperature. The samples were characterized by TG-DTA, FT-IR, XRD, XRF, SEM and UV-Vis. The results showed that the composite nanofibers had good dispersion, large aspect ratio, small diameter, and visible-light optical absorption property. Compared with TiO2//ZnO nanofibers, TiO2/Fe2O3nanofibers appeared greater visible-light absorption property.3. Taking rhodamine B as degradation agents, photocatalytic activities of TiO2, TiO2/ZnO and TiO2/Fe2O3nanofibers were studied. The results showed that calcination temperature, doping quantity of metallic ions, additive amount of catalyst, and pH of degradation solution had some influences on photocatalytic properties. Through analysis of UV-Vis, it was found that TiO2nanofibers doped with0.5%Zn2+or Fe3+, which calcined at600℃, can degrade rhodamine B effectively. Besides, the additive amount of catalyst was100mg/L, and pH of the degradation solution was2. The degradation rates were up to25%and37%, respectively. And TiO2/Fe2O3nanofibers showed better photocatalytic activity.