Preparation Of Nanometer Titanium Dioxide Doped By Iron And The Study Of Photocatalytic Performance

Titanium dioxide is one of the most promising photocatalytic materials,and compared with other semiconductor materials, titanium dioxide has many advantages, such as higher photocatalytic performance,better chemical stability ,nontoxicity and cheapness. But as photocatalytic material,titanium dioxide has two apparent shortages:titanium dioxide is a wide bandgap semiconductor and can only be absorbed by smaller wavelength UV with low utilization of solar energy;Optical electron-hole is easily compound and inefficient. For titanium dioxide photocatalysis of the problems that exist at present, in this experiment we carried out iron-doped titanium dioxide research, hope to raise the photocatalytic activity of titanium dioxide and expand its scope to respond to visible light to enhance the utilization of catalytic light .In this paper, Fe₂O₃ for doping impurities, pure nano-titanium dioxide and iron(Fe³⁺)-doped nano-titanium dioxide powder were prepared by high-energy ball milling. Methylene blue solution as the degradation products of target, the spectrum of titanium dioxide and the absorbance of methylene blue solution were analyzed by UV - Vis spectrophotometer.The results showed that the spectral absorption edge of iron-doped titanium dioxde moved to visible light region and absorption edge of the largest redshift of doping samples is nearly 20nm compared with non-doped sample beneficial for visible light absorption; Photocatalytic properties of titanium dioxide were markedly improved for an adequate number of doping. The best of doping iron(Fe³⁺:TiO₂ mass ratio)is 0.1 percent and photocatalytic degradation rate increased by nearly 20 percent compared with non-doped sample in this experiment.The spectrum of titanium dioxide for different calcination temperature and the degradation rate of methylene blue solution were studied at the same time.The study showed that tempetature had a great effect on spectra absorption edge and degradation rate of methylene blue solution. Spectra absorption edge is the largest in the 500℃and degradation rate also is the largest at the same time in the experiment. The effect of initial concentration of methylene blue and amount of titanium dioxide on photocatalytic degradation rate of methylene blue also had been examined and the results showed that the effect of degradation was the best when the initial concentration was 12mg/L and amount was 0.8g/L.