Low-temperature synthesis of flower-like TiO2 nanocrystals

Flower-like titania nanocrystals were synthesised by hydrolysis of titanium (IV) chloride at a low temperature of 70°C in 6°h, employing nanocrystal cellulose as a morphology controlling agent. Transmission electron microscope (TEM) and high resolution TEM (HRTEM) investigations revealed that the morphology of the nanocrystals was flower-like, and each flower was composed of several nanoneedles with a diameter of 15°20°nm and a length of 100°200°nm. The X-ray diffraction (XRD) results showed that the crystalline phase of the nanocrystals had a strong dependence on the mole ratio of TiCl₄ to H₂O. This low-temperature-prepared TiO₂ exhibited high activity in the photocatalytic degradation of methyl orange in aqueous solution under high-pressure mercury lamp. This study provides a simple and high-efficient method to prepare TiO₂ nanocrystals with high photocatalytic activity at low temperature.