A novel method to synthesize iron oxide nanomaterials: Characterization, properties, and performance on the direct red 80 dye removal from aqueous solution

Abstract In this work, iron-based nanomaterials (IONs-1 and IONs-2) were synthesized from zero-valent iron nanoparticles (IONs-0) and characterized. IONs-1 were synthesized from IONs-0 by hydrogen peroxide treatment, followed by calcination at 350 °C. IONs-2 were synthesized from IONs-0 by sequential treatment with hydrogen peroxide and sodium hydroxide, respectively. IONs-1 presented the following phases: superparamagnetic Fe3+ (7%), α-Fe2O3 (17%), and γ- Fe2O3 (76%). IONs-2 presented the following phases: superparamagnetic Fe3+ (5%), γ-Fe2O3 (51%) and Fe3S4 (54%). Through microscopy images, it was possible to verify that the IONs-1 and IONs-2 exhibit, respectively, nanorod and well-defined nanosheets formats. The specific surface areas of IONs-1 and IONs-2 were 85.37 and 223.84 m2 g-1, respectively. IONs-1 and IONs-2 were used to remove Direct Red 80 dye, resulting in about 100% removal.