Rapid exfoliation of a layered titanate by ultrasonic processing

The application of ultrasound dramatically increases the rate of exfoliation of HxTi2−x/4O4·yH2O (H–Ti) in the presence of aqueous tetrabutylammonium (TBA) hydroxide. The effect of ultrasonication power and processing time on particle size distributions are evaluated. Applied powers of 60–300 W and reaction times of 2–30 min effectively reduce the H–Ti particle size to <100 nm. Both particle size distribution analysis and UV–Vis spectroscopy were used to study the effect of ratio of TBA ion to exchangeable protons in H–Ti; a minimum ratio of TBA/H≥0.5 is required for rapid exfoliation.