Study on successively preparation of nano-TiO2 ethanol colloids by pulsed laser ablation and fluorescence property

Nano-TiO2 colloids have been successively prepared by focused, pulsed laser ablation (PLA) at the interface of solid titanium dioxide and flowing liquid. Three factors influenced the luminescence of the nano-TiO2 colloids. The first factor was the flowing rates of the flowing liquid. The second factor was the pulsed laser output power. The third factor was the age of the colloids. The nano-TiO2 colloids products were characterized by transmission electron microscopy (TEM), ultraviolet visible spectroscopy (UV-vis) and fluorescence spectroscopy. The results revealed that anhydrous ethanol was the best flowing liquid, and cyclohexane or water was found to be not suitable for this system; under the conditions of the lowest flowing rates of the flowing liquids in the range of 0.017-0.15 mL/s, the highest pulsed laser output power in the range of 100-250 mJ/pulse and with the proper aging time of the colloids, nano-TiO2 ethanol colloids with strong fluorescence emission intensity at about 414 nm can be obtained.