Effect of pH on the Formation of Amorphous TiO₂ Complexes and TiO₂ Anatase during Pyrolysis of TiCl₄ 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.