Application of titanate nanotubes for Cu(II) ions adsorptive removal from aqueous solution

The potential of adsorptive removal of Cu(II) ions with titanate nanotubes (TNT) was investigated. TNT was prepared via a hydrothermal treatment of TiO2 powders in a 10 M NaOH solution at 150 °C for 24 h, and subsequently washed with HCl aqueous solution of different concentrations. Effects of the alteration of microstructures of TNT, induced by the acid washing process, on the Cu(II) ions removal performance were discussed. Also examined was the effects of Cu(II) adsorption on the pore structure characteristics of TNT. It was experimentally concluded that if the amount of Na+ in the TNT was not very low, the TNT might be a good adsorbent for the removal of Cu(II) ions from aqueous solution with the adsorption capacity reaching 120 mg/g. The adsorption mechanisms of Cu(II) ions from aqueous solution onto TNT were examined with the aid of model analyses of the adsorption equilibrium and kinetic data of Cu(II) ions.