Preparation, characterization, and growth mechanism of a novel aligned nanosquare anatase in large quantities in the presence of TMAOH

Monodispersed and well-aligned samples of TiO 2 nanosquares were synthesized in large quantities in the presence of tetramethylammonium hydroxide (TMAOH) for the first time. These nanosquares were single crystals characterized by slightly truncated shape bounded by {101} facets. XRD, AFM, FT-IR, Raman scattering, TEM and HRTEM were employed to characterize the as-prepared samples. The possible microreaction mechanism was discussed. As a result, TMAOH accelerates the formation of crystalline anatase and plays a structural template role to modify the particle shape to nanosquare. Moreover, TMAOH reacted with hydrolysates and formed layered structural complex compound. The sol hydrothermally treated at 160 °C for 4 h was investigated by TEM. The anatase nanoparticles with side-length of 10 − 13 nm are nanosquare-shaped, monodispersed, and aligned in large scales.