Effect of pH on the Formation of Amorphous TiO<sub>2</sub> Complexes and TiO<sub>2</sub> Anatase during Pyrolysis of TiCl<sub>4</sub> Aqueous Solution

The TiO2 nanostructures resulted by pyrolysis of TiCl4 at low temperature of 80 oC are found to be a mixture of amorphous TiO2 complexes and anatase nanostructure that depends on the pH of the pyrolysis medium. Anatase nanostructure is predominant at low pH level and gradually converts to amorphous TiO2 complexes with increasing pH level. By means of heat treatment, the TiO2 nanostructures can be recovered from amorphous TiO2 complexes. Amongst of the TiO2 nanostructure recovered from amorphous TiO2 complexes, the anatase nanostructure shows to be the strongest photocatalyst in decomposition of methylene blue.