Efficient removal of heavy metal ions from water system by titanate nanoflowers

Titanate nanoflowers were synthesized through a facile hydrothermal treatment of anatase nanopowders in concentrated NaOH solution. The as-obtained nanoflowers have large specific surface area and show availability for the removal of heavy metal ions from water system. Comparative studies exhibit that titanate nanoflowers possess larger adsorption capacity and more rapid kinetics than titanate nanotubes/nanowires. Furthermore, they also show high selectivity in the removal of highly toxic heavy metal ion (Cd(II)) than less toxic ions (Zn(II) and Ni(II)). This study highlights that titanate nanoflowers are potential adsorbents for efficient removal of toxic metal ions. The adsorption mechanism was also discussed. It is found that the equilibrium data fitted well with the Langmuir model, while the adsorption kinetics followed the preudo-second-order model. (C) 2011 Elsevier B.V. All rights reserved.