Rapid removal of chromium (VI) from aqueous solution using iron oxide/polyaniline nanocomposites

Abstract

Core-shell structured magnetic iron oxide nanoparticles/polyaniline (Fe₃O₄ NPs/PANi) nanocomposite has been successfully synthesized by a two-step chemical precipitation-polymerization route, and was characterized using transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR), and X-ray diffraction (XRD). Fe₃O₄ NPs/PANi nanocomposite was used as adsorbent to remove hexavalent chromium (Cr(VI)) ions from aqueous solution.The equilibrium data were well fitted the Langmuir isotherm model. The maximum adsorption capacity of Fe₃O₄ NPs/PANi nanocomposite for Cr(VI)  is 76.9 mg.g^-1. The adsorption mechanism has been identified as an ion exchange and a redox mechanism, based on X-ray photoelectron spectroscopy (XPS) study. Our study shows that magnetic Fe₃O₄ NPs/PANi nanocomposite is a promising adsorbent for rapid removal of Cr(VI) from aqueous solution.