Mesoporous Sn@TiO2 nanostructures as excellent adsorbent for Ba ions in aqueous solution.

Efficient adsorption of Ba ions was achieved using Sn@TiO 2 nanocomposite generated by ultrasonication process with subsequent calcination at 300 °C. X-ray diffraction, nitrogen adsorption-desorption isotherm, X-ray photoelectron spectroscopy, Fourier transformer infra-red, and scanning/transmission electron microscopy analyses were performed to probe the structural and textural features of the adsorbent powder. The XPS, FTIR, and EDX analyses confirmed the Sn doping into TiO 2 host lattice. Some interesting features, including the increase of crystallite size and lattice parameters, were attained due to the successful Sn incorporation into the TiO 2 host, as indicated further by XRD analysis. The sorption results fitted the Langmuir isotherm model and the kinetic data complied with the pseudo-second-order kinetics. The adsorption process improved markedly above the pHzc due to the electrostatic attraction between the negatively charged Sn@TiO 2 particles' surface and the positively charged Ba ions. The achieved high-performance mesoporous Sn@TiO 2 nanostructures for the adsorption of Ba2+ could be potentially utilized to remove other toxic metal cations. [ABSTRACT FROM AUTHOR]