Protonated Titanates and TiO₂ Nanostructured Materials: Synthesis, Properties, and Applications

Abstract

Tubular and fibrous nanostructures of titanates have recently been synthesized and characterized. Three general approaches (template assisted, anodic oxidation, and alkaline hydrothermal) for the preparation of nanostructured titanate and TiO2 are reviewed. The crystal structures, morphologies, and mechanism of formation of nanostructured titanates produced by the alkaline hydrothermal method are critically discussed. The physicochemical properties of nanostructured titanates are highlighted and the links between properties and applications are emphasized. Examples of early applications of nanostructured titanates in catalysis, photocatalysis, electrocatalysis, lithium batteries, hydrogen storage, and solar‐cell technologies are reviewed. The stability of titanate nanotubes at elevated temperatures and in acid media is considered.

Physico-chemical properties and possible photocatalytic applications of titanate nanotubes synthesized via hydrothermal method

“…The Type H3 loop is observed with aggregates of plate-like particles giving rise to slit-shaped pores [47]. Taking into consideration that titanate nanotubes are multiwalled scrolls which are believed to be formed through sheet folding or wrapping mechanism [9,15] it seems to be reasonable that they exhibit the H3 loop. The surface properties of TNTs determined on a basis of N 2 adsorption -desorption measurements are presented in Table 1.…”

“…According to Bavykin et al [15] the method accounts for the pores not only inside the tubes but also for the pores between the tubes.…”

“…In the "Introduction" section of numerous papers [11][12][13][14][15] it can be found that titanate nanotubes have potential applications in photocatalysis. However, the data on this subject which are presented in literature are rather limited and inconsistent.…”

Growth of TiO2 nanotube arrays with simultaneous Au nanoparticles impregnation: photocatalysts for hydrogen production

“…7,8 One of the biggest limitations of TiO 2 is its relatively large band gap between 3.0 and 3.2 eV. 9 Therefore, only UV light can be utilized for hydrogen production. Since UV light only accounts for about 5% of the solar radiation that reaches Earth's surface, the inability to utilize visible light limits the efficiency of solar photocatalytic hydrogen generation.…”

Interaction of sodium titanate nanotubes with organic acids and base: chemical, structural and morphological stabilities

“…1 In particular, titanate nanotubes have attracted great attention from the scientific community due to their potential applications in biosensors, electronic, optical, magnetic, electrochromic and solar cell devices, as well as in heterogeneous photocatalysis. [2][3][4][5][6][7][8][9] Additionally, 1D titanate nanostructures have also been used as support for the immobilization of myoglobin, 10 and as host for platinum oxide and lithium intercalation. 11,12 Titanate nanotubes can be prepared by hydrothermal treatment of TiO 2 powders (anatase or rutile) in aqueous NaOH solutions.…”