Iron Oxide Supported Sulfhydryl-Functionalized Multiwalled Carbon Nanotubes for Removal of Arsenite from Aqueous Solution

Magnetic iron oxide/carbon nanotube (MI-CNT) hybrids have been successfully synthesized through a simple solid-phase method by using as-prepared CNTs (APCNTs). To further enhance the adsorption capacity for As-III, MI-CNTs were subsequently functionalized by using an amino acid derivative (glutathione (GSH)) through a facile chemical route. CNTs not only act as a support for iron oxide but also significantly contribute to arsenic removal. The resulting GMI-CNTs possess simultaneously a high adsorption capacity and desirable magnetic properties, thus making them promising for use as an adsorbent to remove As-III with significantly enhanced adsorption capacity (19.12mgg(-1)) and desired magnetic separation properties (M-s=27.3emug(-1)). Adsorption studies indicated that the active sites on the surface of GMI-CNTs for As-III are heterogeneous owing to the multiphase of Fe and the GSH functionalization. Therefore GMI-CNTs can potentially be used as a practical adsorbent for the decontamination of As-III in water. The results of this study are highly important for practical applications of as-prepared CNTs that contain catalyst nanoparticles.