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 CeO 2 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.

Cobalt Hexacyanoferrate-Decorated Titania Nanotube: CoHCF@TNT Modified GCE as an Electron Transfer Mediator for the Determination of Hydrazine in Water Samples

“…This red shift in the band edge absorption can be understood as being due to the effects of CoHCF addition (intercalation), which change the band gap energy of the system. A similar band gap shift toward the visible range was also observed for TNTs intercalated with other metals, such as Fe, Bi, Cd, Ni, and Co [43]. By using standard Kubelka-Munk methodology, we can estimate the band gap for TNT and CoHCF as being 3.06 and 2.94 eV, respectively.…”

“…In addition, the absorption bands at 3404 and 1608 cm −1 indicates the O-H stretching mode and H-O-H bending mode, respectively. These results highlight the presence of water molecules in a interstitial position, and also the stretching vibration of water molecules produces another broad peak at 3635 cm −1 which further confirm that the samples are hydrated [40,43,45]. We have compared the current density and the peak potential changes of bare and CoHCF@TNT-modified electrodes on electrocatalytic oxidation of hydrazine, and the resulting cyclic voltammograms are shown in Figure 6.…”

“…By using standard Kubelka-Munk methodology, we can estimate the band gap for TNT and CoHCF as being 3.06 and 2.94 eV, respectively. The photoabsorption of CoHCF@TNT in the range 410-760 nm is attributed due to the existence of the Co 3d bands above the O 2p bands [43,44].…”

Tungstate/titanate composite nanorod as an efficient visible light photo catalyst

“…As the calcination temperature increases, the band edge absorption shifts more to visible region which enhances the photo catalytic activity up to 800 • C. This red shift in the band edge absorption can be understood as being due to the effects of the presence of tungsten, which change the band gap energy of the system. By using standard Kubelka-Munk methodology, we estimated the band gap for our composite at 800 • C as being 2.90 eV, which is lower than the 3.45 eV band gap of sodium titanate [62].…”

Controlled synthesis and magnetic properties of monodispersed ceria nanoparticles

“…The large surface-to-volume ratio of nanostructures provides another approach for developing a new generation of functional and smart materials, which opening up the opportunity to start a new era in the field of technology. 1 Cerium oxide (CeO 2 ), commonly known as ceria has a cubic structure. It is one of the most important oxides of the member of rare earth.…”