Reaction morphology and the effect of pH on the preparation of TiO2 nanoparticles by a sol-gel method

Titanium dioxide nanoparticles were prepared by hydrolysis of titanium tetra-isopropoxide. Aqueous solutions with various pH and the resultant reaction morphology on the preparation of TiO2 nanoparticles were investigated. The influence of pH on the reaction morphology of using a titanium tetra-isopropoxide was evaluated depending on the amounts of the catalysts such as HCl and NH4OH. The morphology and phase transformation of TiO2 particles prepared by the hydrolysis of titanium tetra-isopropoxide were strongly influenced by the presence of the catalysts. In the case of using NH4OH, the morphology of the TiO2 particles exhibited a powder form. In the case of using HCl, it showed a bulk or granular form. The phase transformations of amorphous Ti(OH)(4) to anatase TiO2 and the anatase to rutile were significantly influenced by the type and the amount of the catalysts.