Degradation of rhodamine B using FeS-coated zero-valent iron nanoparticles in the presence of dissolved oxygen

In this study, we have developed a novel and simple method to prepare Fe/FeS core-shell nanoparticles using thioacetamide. The Fe/FeS nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) in conjunction with EDX analysis. The performance of Fe/FeS nanoparticles was evaluated as catalyst to activate molecular oxygen for Rhodamine B (RhB) removal in aqueous solution. The Fe/FeS nanoparticles shows a much higher reactivity on the activation of molecular oxygen than the pure Fe nanoparticles. A complete set of control experiments were conducted to optimize the reaction conditions, including the dosage of Fe/FeS nanoparticles, the RhB concentration, as well as the initial pH value. Moreover, the free radical quenching studies indicated the generation of the reactive oxygen species, namely hydroxyl radicals (•OH) and superoxide radical anions ( O2•−), and •OH is the predominant one in Fe/FeS-activated molecular oxygen system. The study reveals that Fe/FeS nanoparticles are a promising candidate for the efficient removal of pollutants. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1673–1678, 2016