Fine size-regulation of nanocrystalline anatase-TiO2via sol–gel synthesis and subsequent phase transformation by calcination

Nanocrystalline TiO2 particles were prepared via the sol–gel process. The particle size and nanostructure of the TiO2 sol were controlled through the ageing process accompanied by hydrolysis–polycondensation. The resultant TiO2 particles were analysed by BET, HR-TEM, PSA, TGA, turbidity, XRD, and zeta potential analyses. The TiO2 size increased with increasing ageing time and reaction temperature. A phase transformation from anatase to rutile occurred with heat treatment at 500 °C. The phase transformation is strongly influenced by the primary particle sizes of TiO2, which were characterised via XRD and Raman spectroscopic analyses.