Plasmonic and magnetic nanostructures as photocatalysts in the arsenic oxidation and removal from water

Abstract

We developed a synthesis protocol of bifunctional catalytic nanostructures, with plasmonic and magnetic properties, composed by gold nanospheres adsorbed on a Fe₃O₄ magnetic core, to be used in the remediation of arsenic-containing water. The design is based on gold nanoparticles acting as catalysts in the oxidation of the As(III) species to the less toxic As(V), and under resonant illumination further accelerating the reaction. The Fe₃O₄ surface acts as an active site for arsenic adsorption and can be easily removed from water by a magnet. We study the adsorption isotherms and the optical and magnetic response of this nanosystem.