Effective and Selective Sorption of Iodide by Thin Film of Multilayered MnO₂ Intercalated with Cationic Surfactants

Abstract

We have fabricated a thin film of multilayered MnO₂ whose interlayer is occupied with hexadecylpyridinium (HDPy) cations, using a simple anodic approach. The resulting film can effectively sorb iodide anions from aqueous solutions, even in the presence of NaCl or Na₂SO₄. The maximum sorption capacity was estimated to be 256 mg/g-MnO₂, whereas a layered MnO₂ film intercalated with K⁺ ions showed no significant sorption. The layered structure of the HDPy/MnO₂ composite remained unchanged after a sorption experiment. This indicates the incorporation of I⁻ ions between MnO₂ layers due to their specific affinity toward HDPy.