Preparation,Characterization And Photocatalytic Activity Of Nano-TiO₂

Nanoscale TiO₂ can totally decomposite organic pollutants into small molecular substances such as CO₂ and H₂O by solar light.TiO₂ has been attracted a great deal of attention because of its non-toxicity,high catalytic activity and good stability upon the degradation of organic pollutants.However,TiO₂ nanoparticles are likely to agglomerate in the water due to its small particle size;Moreover,TiO₂ has a wide band gap and the low utilization ratio of energy.This dissertation mainly adopts the non-hydrolytic sol–gel method to prepare the water-dispersible TiO₂nanoparticles and the influence of different reaction conditions on the structure of TiO₂ and its photodegradation of RhB under visible light irradiation.To enhance the absorption of visible light and narrow the band gap of TiO₂,Fe-Cu co-doped TiO₂ were synthesized through a nonaqueous method.The main results are as follows:?1?By controlling the concentration of reactants,reaction time,reaction temperature,oxygen donor of the experimental parameters to prepare a series of aqueous dispersion of TiO₂,.The experimental results show that the prepared TiO₂ nanoparticles.were about 10nm in diameter and was a typical structure anatase,high specific surface area and good water dispersibility according to characterizations with X-ray diffraction,transmission electron microscopy,specific surface area and water dispersion.With the increase of concentration,the grain size of TiO₂ are decreased and the light transmittance of the aqueous dispersion decreased;with the increase of reaction time,the grain size of TiO₂ increased and light transmittance of the aqueous dispersion decreased;with the temperature from 150^o C to 170^oC,the size and the light transmittance of the aqueous dispersion of TiO₂ nanoparticles has no great change;the light transmittance of the aqueous dispersion TiO₂ was preparaed using the ethanol as an oxygen donor was better than n-butyl alcohol as oxygen donor aqueous.?2?According to the result ofphotodegradation of RhB under visible light irradiation,the optimum condition is the oxygen donor is ethanol,reactant concentration was 52%,reaction time was 6h,temperature of150?.We also research the degradation of pollutants formaldehyde,the results showed that TiO₂ prepared at a wavelength of 254nm UV light degradation exhibit the optimum catalytic activity;TiO₂ of dispersion was5%exhibit the highest photocatalytic effect;with the concentration of formaldehyde increased,the photocatalytic degradation efficiency increased,but when the concentration of formaldehyde up to a certain value,photocatalytic activity decreased.?3?Fe-doped TiO₂ and Fe-Cu co-doped TiO₂ photocatalyst was prepared via a facile non-hydrolytic sol–gel route.The resulting Fe-Cu co-doped TiO₂ photocatalyst were about 10nm in diameter and was a typical structure anatase according to transmission electron microscopy?TEM?,X-ray diffraction?XRD?.During photodegradation of RhB under visible light irradiation,the Fe-Cu co-doped TiO₂ photocatalyst exhibited a higher activity than either the undoped TiO₂ or the Fe-doped TiO₂.Furthermore,the highest photocatalytic activity of products observed with1 mol%and 1mol%of Fe and Cu contents as photocatalysts,respectively.