What kind of method did you use for synthesis TiO2? The best ways  to figure out the purity of your products are EDX and XRD. I mean you can not judge just by visual analysis.

for synthesis TiO2 used of sol-gel methods. did you synthesis TiO2 with this methods?

Dear Mostafa

Yes I did. Just calcined  it at 500 for h.

if you need more information let me know 

Dear Omid

TBOT precursor is yellow. the gel dried at 80 for 24 h and obtained yellow powder calcined at 400 for 2 h.

thanks

I think it is better to calcined it at 500.  I used TEOT and calcined it at 500. it was pure.

Hi 

the following article may be very helpful.. 

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8275331&fileId=S1946427411007597

you can also download it from my profile

Thanks  

Yellow TiO2  powder maybe attributed to partial surface defects, such as Ti3+ and O vacancy. And if its surface contains many hydroxyls, the yellow color will be observed, as we find.

May I ask what phase you are getting by XRay diffraction patterns? All TiO2 phases are not white.

Dear Varun Chaudhary,

     Our result shows that the yellow TiO2 powders show  broad diffraction peaks of anatase TiO2 but an extra diffraction peak occurs at 2 theta=~8. We are trying to find out this peak belonging.

It shows that your TiO2 is not completely converted to Anatase TiO2, keep on increase calcination temperature by 50 degree also increase the calcination time to 2-4 h. I hope at 500 degree you may get pure white tio2 but u need to keep it for longer time...

TiO2 not converted fully anatase phase it having high rutile phase, calcination to be proceed very control manner upto elivated temperature and time