Using Titanium Dioxide–Nanostructures for the Removal of Lanthanide Ions from Water Samples

The nanoparticle metal oxides exhibit intrinsic surface reactivity and high surface areas, and can strongly chemisorb many substances, such as acidic gases and polar organics [1]. Vassileva and Hadjiivanov investigated the surface chemistry of high surface area oxides, e.g. TiO2, ZrO2, CeO2 and ZnO and found that these materials have a very high adsorption capacity towards metal ions and give promising results when used for trace elements analyses of different samples [2]. In this study, titanium dioxide nanoparticles (TiO2 NPs) and supported TiO2 NPs on silica gel were synthesized. These nanostructures were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Adsorption property of TiO2 powder was compared with TiO2 NPs and supported TiO2 NPs for separation of trace amounts of La, Dy, Ce, Sm and Nd from aqueous media. The effects of pH and contact time on the adsorption behavior were investigated. It was found that, the metal ions can be quantitatively adsorbed and removed in the pH above 8. Under optimum conditions, TiO2 NPs possess a better potential as an adsorbent than others. The adsorption capacity of TiO2 NPs and supported TiO2 NPs was higher than TiO2 powder in the pH range of 8-9