The results showed that 400oC was an optimum calcination temperature for the as-synthesized
TiO2 powder.
It was high enough to achieve crystallization, and at the same time, helped minimize the thermal growth of the crystallites and maintain nanoscale features in the calcined powder.
After calcination at 400oC (3 h), XRD results showed that the synthesized nano-TiO2 powder was mainly in single anatase phase.
Crystallite size was first calculated through XRD,