Decorating Titanate Nanotubes with CeO₂ Nanoparticles

Abstract

In this work, we report the synthesis, characterization, and application of Ce ion-exchanged titanate nanotubes (Ce-TiNTs). The physicochemical properties of these Ce-TiNTs are discussed in comparison with their pure titanate nanotube counterparts. The transmission electron microscope images showed that the Ce-TiNTs have the same morphology as that of pristine nanotubes and their external walls are decorated with cerium oxide nanoparticles. The mechanism of nanoparticle formation is based on the precipitation of Ce ions at the nanotube surface. We observed a red shift of the absorption band edge toward the visible region whose main contribution comes from the Ce ion intercalation. A red shift of vibrational modes associated with metal ion−oxygen interaction was observed and identified as being due to the effect of Ce addition to the lattice as well as the anchoring of CeO2 nanoparticles to the nanotube wall. We show that this hybrid system is promising for applications in photocatalysis using the blue region of the electromagnetic spectrum. This was demonstrated for photodegradation of Reactive Blue 19 textile dye.