Morphology, crystal structure and adsorption performance of hydrothermally synthesized titania and titanate nanostructures

Titania (TiO2) and sodium titanate nanostructures with controllable phases and morphologies were synthesized by a hydrothermal method with titanium disulfide (TiS2) as the starting material. Sodium titanate nanobelts could be synthesized under a relatively low alkaline concentration (1 mol L−1 NaOH) and short duration (6 h). At 3 mol L−1 HCl, rutile TiO2 nanorods were synthesized. Anatase TiO2 nanoparticles were obtained at pH values ranging between 2 and 13. FTIR analysis confirmed the phase change as the pH of the reacting medium increased from highly acidic to highly alkaline. The adsorption of Methylene Blue (MB) on the as-synthesized sodium titanate nanobelts fitted well with the Langmuir monolayer model, with an adsorption capacity as high as 312.5 mg g−1. The kinetics of MB adsorption was found to be a pseudo-second-order kinetic model. In brief, this study demonstrates a simple method to control the phase and morphology of titanium-based oxides. Excellent performance has been shown in the MB adsorption test by the sodium titanate nanostructures.