Preparation And Characterization Of Mesoporous Anatase Titania Nanocrystals Through Sonochemical Method And Its Water-treatment Functionalization

It is well-known that photocatalytic technique of nano-semiconductor represented by titanium dioxide is suitable to degrade organic pollutants in water supply, wastewater and water reuse. However, there are many problems in large-scale application, which make photocatalytic technique in wastewater application stagnant. In this paper, the high-activity mesoporous titania Photocatalysis preparation, conditions, characterization and primary application were mainly studied in three parts.In first part, low temperature sonochemical synthesis was employed to prepared mesoporous TiO₂ without adding templates. Well-dispersed and one-step crystallized anatase mesoporous nanoparticles could be prepared directly, and it exhibits highly photocatalytic activity after calcination of 450℃, 15 percent better than that of conventional hydrolysis. Sonochemical method is easy and fast. It could accelerate the hydrolysis of tetrabutyl titanate (TBOT), the crystallization of TiO₂ and the formation of mesoprous structure. It would give a new path for photocatalytic technique in wastewater treatment.In second part, nanosized iron-doped TiO₂ powders were prepared by somochemical method with tetrabutyl titanate as precursor, structure-directed with different amounts of dodecylamine (DDA) in a mild condition within a short duration and iron nitrate as iron source, which were characterized by TG/DTA, TEM and XRD techniques. The results showed that after the calcination, the particals exhibit worm-like mesoporous pore structure and sphere. All of the titania prepared in the condition are anatase titania. Iron was proved to be doped into the titania to enhance the photocatalitic activity of titania. 5% mole percentage of Fe/Ti was the best doped concentration. It has higher activity than the one without iron doped.In third part, tetrabutyl titanate was also used as Ti source and dodecydiamine(DADD) were employed in preparation of TiO₂ through sonochemical method, triethanolamine as hydrolysis inhibitors. Morphology, crystallization and pore structure of nanoparticals could be controlled by the addition of DADD, the initial reaction pH value, washing method, and calcination temperature. The morphology and pore size controlled anatase titania was prepared directly by sonochemical method. On the other hand, sonochemical process was proved as a short and simple way for the preparation of mesoprous TiO₂ nanoparticals under low temperature and short time(80℃, 6 hours). The Result showed that it has not only high photocatalytic activity but also good thermal stability, which resolved the bottleneck problem of non-silicon mesoporous materials and provides a new growth point in the controllable preparation of mesoporous titania nanoparticals.