Characteristics of nano rosette Tio₂ hydrothermally grown on a glass substrate at different reaction times and acid concentrations

The characteristics of nano rosette TiO₂ hydrothermally grown on a glass substrate at different reaction times and acid concentrations has been examined. The hydrothermal reaction was performed at 170°C for 3, 4, 5, and 6 hours whereas the crystallization was achieved through calcination at 450°C for 90 minutes. The growth mechanism was observed by employing the hydrothermal reaction under different acid concentrations: 0%, 12.5%, 25%, and 50% v/v HCl. The morphology, formation, crystallization, and growth mechanism of the nano rosette TiO₂ were characterized using a field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD). The electron images showed that after 3 hours of hydrothermal reaction time, the nucleation process has just taken place; the formation of the nano rosette was completed after 6 hours. The results also showed that the acid environment plays a dominant role in determining the three-dimensional (3D) architecture of the nano rosette TiO₂. Structural studies from XRD showed that different acid concentrations resulted in different crystalline formations. The nano rosette rutile TiO₂ crystal structure was formed after 6 hours of hydrothermal reaction under 1:1 distilled water and HCl with a structure indexed to rutile P4₂/mnm with lattice parameters of a = 4.557(6) Å and c = 2.940(5) Å.