Micro Structural Control Of Nano Tio <sub> 2 </ Sub> And Its Photocatalytic Activity Study

The microstructure of nano-TiO2 including average radis, size and crystalline were discussed. Moreover this article emphasised on the control of geometric shape of nano-TiO2 particle, the effect on surface of nano-TiO2 doped by oxides and sulphides that was characterized by photocatalytic activity.Nano-TiO2 particles with a certain geometric shape, good dispersion and photocatalytic activity were prepared by W/O micro-emulsion using span-80 as surfactant. When nano-TiO2 were prepared by the pyrolysis method, the cooling process of products was based on treatment in silicone oil. The results showed that modified TiO2 sample has no obvious difference in phase ,size, crystalline and photocatalytic activity , but has greatly reduced agglomeration of particles so that it can suspend on the surface or upside lay of water for a long time. However TiO2 solid solution particles can be formed in the calcining process at high temperature doped by Fe3+, Zn2+and Ni2+, and low photocatalytic activity. The different sulphides such as ZnS, NiS and CdS modified nano-TiO2 ,which has also no notable effect on the microstruction. Their order of photocatalytic activity is TiO2-ZnS>TiO2-CdS>TiO2-NiS. Furthermore, the thermal stability of CdS was discussed,too.