The Effect of Ionic Charge on the Adsorption of Organic Dyes onto Titanate Nanotubes

Abstract

The adsorption of dye molecules from aqueous solution onto the surface of titanate nanotubes (which have been synthesized via an alkaline hydrothermal treatment) has been studied. The ionic charge on the dye molecules was found to affect their ability to adsorb onto the titanate nanotube surface. In the case of (cationic) methylene blue, the adsorption was preferable on the negatively charged surface of titanate nanotubes rather than on positively charged P25 TiO2 nanoparticles. In the case of (anionic) Eriochrome Black T dye, the opposite trend was found. Herein, the dynamics of dye adsorption and the effect of pH on the adsorption capacity are considered.