A facile solution approach for the synthesis of akaganeite (β-FeOOH) nanorods and their ion-exchange mechanism toward As(V) ions

Akaganeite (beta-FeOOH) nanorods with a hollandite-type structure were prepared by a simple solution method, and were characterized by X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy and nitrogen adsorption-desorption isotherms. The ion-exchange properties of the nanorods toward As(V) ions were investigated. The ion-exchange mechanism between the surface hydroxyl groups and As(V) ions was revealed by FTIR and XPS. From the results of the experiments, it is found that the surface hydroxyl groups which hydrogen bonded water molecules located outside of the hollandite channels play key roles in the ion-exchange process. In addition, the as-prepared beta-FeOOH could be readily regenerated using NaOH solution and be repeatedly used. (C) 2013 Elsevier B.V. All rights reserved.