| Nanosized TiO2-based photocatalytic oxidation is a promising method for sewage treatment and air purification, which, by virtue of its strong oxidation power, can decompose most organic pollutants and mineralize them into CO2, H2O and other small inorganic molecules completely. This technology possesses many merits such as strong oxidation power, low cost, high efficiency, easy operation, innocuity, no secondary pollution and etc., which suggests its promising application. But, the band-gap energy of TiO2 is big (Eg=3.2eV) and UV light (λ≤387.5nm) irradiation is needed for the photocatalytic reaction, which confines effective utilization of solar energy and so confines its large-scale application. At present, the core point in this technology is to develop new nanosized TiO2, which is Vis-light responsive, possesses high quantum yield and is of lower cost.In this dissertation, the more available and cheaper inorganic TiCl4 was used as raw matearl to prepare nanisized TiO2 by hydrolysis. XRD, SEM were employed in the influence analysis of initial Ti concentration, hydrolysis temperature and addition of SO42- on particle size, morphology and phase composition. And spheral TiO2 crystals around 34nm with controllable phase composition were successfully prepared.Nitrogen doped and sulfur doped TiO2 nanocrystals were synthesized through a mehcanocamical method. Here, the dry hydrous titania from hydrolysis of TiCl4 aqueous solution (the above-mentioned nanosized TiO2 was obtained from calcination of the dry hydrous titania) was used as precursor and ammonium carbonate and thiourea were used as N and S source. XRD, SEM...
|
PDF Full Text Request