Elongated Titanate Nanostructures and Their Applications

Abstract

Recent advances in the synthesis, characterisation and applications of elongated titanate and TiO2 nanostructures (including nanotubes, nanofibres and nanorods) are reviewed. The physicochemical properties of nanostructures, such as high surface area, efficient ion‐exchange properties, electron and proton conductivity and high aspect ratio, are described in connection with a particular application. Practical aspects of the preparation, stability and transformation of elongated titanates are considered. A critical survey of the literature is provided together with the development of prospectiveenergy applications of elongated titanates in catalysis, photocatalysis, electrocatalysis, solar cells, fuel cells, lithium batteries and hydrogen storage. Other applications utilising the high aspect ratio of elongated nanostructures include biomedical implants, sensors, drug delivery systems and smart, tribological composite coatings. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

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

“…[41] Titanate nanotubes decorated with dye molecules have potential application in dye sensitized solar cells. In typical cell manufacturing processes, the suspension of nanotubes is deposited on the surface of electro-conductive glass followed by calcination at 450 • C. Such high-temperature thermal treatments results in structural and morphological changes of nanotubes, [5,42] which may affect the affinity of dye molecules for the surface of the semiconductor.According to recent reports, [43] annealing of protonated titanate nanotubes (H-TiNT) at 400 • C results in a 34% decrease of their specific surface area, accompanied by loss of water molecules and transformation of titanates to monoclinic TiO 2 (B), [42] maintaining nanotubular morphology. Analysis of MB adsorption isotherm on the surface of annealed samples have revealed that calcination of protonated nanotubes in air at 400 • C for 24 h results in ∼30% decrease of the amount of MB molecules forming the monolayer on the surface of nanotubes (a s ) and 75% decrease of adsorption constant K L ( Table 1).…”

“…Nanotubular titanates, which were originally discovered by Kasuga et al [4] can be potentially used in applications [5] such as catalysis, [6,7] photocatalysis [8,9] and electrocatalysis, hydrogen storage, [10,11] lithium batteries, [12,13] and solar cells. [14,15] The open, mesoporous morphology, high aspect ratio combined with good ion-exchange properties [16,17] and moderate electroconductivity render nanostructured titanates useful in nanoscale design.…”

Insights into the multistep transformation of titanate nanotubes into nanowires and nanoribbons

“…These materials are synthesized by various techniques, however the alkaline hydrothermal method is regarded as the most attractive because of its simple procedures and low cost [6]. Nonetheless, the mechanism of nanostructured titanate materials formation and the method providing the control of morphology (specific shape of material, diameter and length, size distribution) are still the subject of intense research efforts [7]. What is more, our literature survey shows that authors describing titanate structures formed through alkaline hydrothermal treatment have used terms nanoribbons, nanowires, nanorods, nanofibers, nanobelts interchangeably [8].…”

Synthesis Optimization and Characterization of Visible-light Responsive Ce-doped Titanate Nanotubes for Enhanced Degradation of Polluting Dyes in Aqueous Environment

“…Titania nanotube is expected to be a high performance photocatalyst, because titania nanotube has a large surface area, high adsorption ability with ion exchange capacity and superior charge transport property (Bevykin and Walsh, 2009;Herández-Alonso et al, 2011). Kasuga et al (1998) discovered a simple synthetic method for the preparation of titanate nanotubes.…”