Research On Tio₂ Degradation Effect Upon Mb Combining With Visible Light

In this paper, we apply Fe-doped and La-doped modification methods to improve the photocatalytic activity of pure TiO2,the utilization of visible light and treatment effect of the organic wastewater.Modified TiO2 doped Fe and La are prepared by sol-hydrothermal method and compared with self-made pure TiO2 in the degradation capacity.Based on the experiment, the best ratio of reactant (volume ratio) is ensured, ethanol: deionized water:acetic acid:butyl titanate=10:2:1:2.Optimal water temperature is 180℃.The best hydrothermal time is 8h,Optimal Fe3+ doping quantity is 1.0%(molar percentage) and optimal La3+ doping quantity is 1.0%(molar percentage).Absorption properties and photocatalytic properties of TiO2 are applied into methylene blue water is researched.Ordinary incandescent lamp simulates visible light source.Research shows that:After about 2.5h the TiO2 adsorption upon methylene blue reach to a balance when 25℃,pH=10 and the dosage of TiO2 is 0.2g/L.The saturated adsorption of pure TiO2 is 14.81mg/L,Fe3+-doped TiO2's is 16.13mg/L,La3+-doped TiO2's is 18.18mg/L. TiO2 has good absorbing function when methylene blue concentration is 5mg/L and 10 mg/L respectively. The best conditions of TiO2 degradation:illumination time is 4h, pH is 10,catalyst quantity is 0.04g, the initial concentration of methylene blue solution is 5mg/L.Under the best degradation conditions,the degradation rate of methylene blue by pure TiO2 can reach 53.17%,the degradation rate of methylene blue by Fe3+-doped TiO2 can reach 67.38% and the degradation rate of methylene blue by La3+-doped nano-TiO2 can reach 77.76%.The experimental data shows:TiO2 combined with Fe3+ and La3+ can improve the photoc-atalytic activity of TiO2,and the photocatalytic activity of TiO2 doped La3+ is higher than TiO2 doped Fe3+.