Influence of Na+ content on the structure and morphology of TiO2 nanoparticles prepared by hydrothermal transformation of alkaline titanate nanotubes

摘要

The objective of this study is to investigate the role of Na~(+) content in the morphology evolution of TiO_(2) nanoparticles prepared by hydrothermal approach. Various TiO_(2) morphology from 0-dimensional (0D) nanoparticles to 1-dimensional (1D) nanorods were synthesised by hydrothermally treating the alkali titanate nanotubes with different Na~(+) content. The XRD patterns show the phase transformation and crystallographic nature of alkali titanate nanotubes are strongly dependent on the Na~(+) content, the cation exchange of Na~(+) by H~(+) ion exchange affects the crystallinity of the tubes and causes disorder of the interlayers of nanotubes. The SEM and TEM images confirm that Na~(+) rich titanate nanotubes were thermally stable. Moreover, BET measurements revealed that the Na~(+) content plays an important role on the specific surface area of formed TiO_(2) nanoparticles. The photocatalytic activity of the TiO_(2) nanoparticles was characterised via the decomposition rate of an aqueous solution of methyl orange (MO) under UV light irradiation. The TiO_(2) nanoparticles prepared by hydrothermally treating the alkali titanate nanotubes with no Na~(+) content has a surface area of 55.1 m~(2)/g with nearly 100% photodecomposition of MO in 20 min.