Effects of Alkalinity on the Hydrothermal Synthesis of Lead Titanate Nanotube Arrays

The alkalinity of hydrothermal solution was proved to have significant effects on the formation of lead titanate nanotube arrays. Using anodic TiO2 nanotube arrays as templates, lead titanate (PbTiO3) nanotube arrays were obtained by in situ hydrothermal synthesis in an alkali-free solution. The addition of KOH in hydrothermal solutions induced a dissolution-precipitation process, which resulted in the formation of cubic PbTiO3 particles instead of nanotubes. Compared with bulks, the nanotubular structure in PbTiO3 nanotube arrays is responsible for the differences in the Raman spectra for different specimens.