Facile synthesis and characterization of functionalized, monocrystalline rutile TiO₂ nanorods

Functionalized, monocrystalline rutile TiO₂ nanorods were prepared from TiCl₄ in aqueous solution under acidic conditions in the presence of dopamine, followed by aging and hydrothermal treatment at 150°C. The surface-bound organic ligand controls the morphology as well as the crystallinity and the phase selection of TiO₂. The presence of monocrystalline rutile TiO₂ was confirmed by X-ray powder diffraction and HRTEM investigations. The as-prepared nanorods are soluble in water at pH <3. The surface functionalization was analyzed by IR and ¹H NMR, confirming the presence of dopamine on the surface. The surface amine groups can be tailored further with functional molecules such as dyes. Confocal laser scanning microscopy (CLSM) was used to characterize the binding of the fluorescent dye 4-chloro-7-nitrobenzofurazan (NBD) to the functionalized surface of the TiO₂ nanorods.