Preparation of ultrafine TiO2 nanocrystals via pulsed-laser ablation of titanium metal in surfactant solution

This work reports the attempts to perform pulsedlaser ablation in a liquid medium for synthesizing oxide semiconductor nanocrystalline particles. Ultrafine TiO2 nanoparticles were synthesized by pulsed-laser ablation of a titanium target immersed in an aqueous solution of surfactant sodium dodecyl sulfate (SDS) as well as in deionized water. The surfactant concentration dependence of TiO2 nanocrystal formation was systematically characterized by X-ray diffraction, optical transmission spectroscopy, and transmission electron microscopy. The maximum amount of ultrafine anatase nanocrystalline particles ( with mean size of 3 nm in diameter) was obtained in an aqueous solution of 0.01 M SDS. A probable formation process was proposed based on laser-induced reactive quenching at plasma-liquid interfaces and surfactant-mediated growth in a liquid solution.