Effect of reaction temperature and sonication pretreatment in the hydrothermal process on the morphology of titanate nano-structure

Abstract

Titanate nanostructures were synthesized by hydrothermal technique. The sonication pretreatment and reaction temperature were employed to investigate the morphology and specific surface area of the titanate nanostructure. Transmission electron microscopy, dynamic light scattering, and nitrogen adsorption were used to characterize and elucidate the behavior of titanate nanostructures in each experimental condition. By the effect of sonication pretreatment, the length and BET surface area of titanate nanotubes (TNTs) were raised from 50 nm to 490-1760 nm and from 180 to 260 m2g-1, respectively, because of de-agglomeration of TiO2 particles in the precursor. The BET surface area of TNTs increased with increasing hydrothermal temperature from 90 to 150°C However, when the reaction temperature increased up to 180°C, BET surface area of TNTs inversely decreased. The reason of the decline in surface area could be explained by morphology of titanate formed. The nanotube structure (hollow) of titanate was transformed to nanofiber structure (non-hollow) at this high temperature. © 2009 The Society of Chemical Engineers, Japan.