Catalytic oxidation of alcohols catalyzed by gold-coated iron oxide magnetic nanoparticles in water

Gold-coated magnetic iron oxide nanoparticles (ION) (Fe₃O₄@Au) were synthesized and utilized as catalyst for alcohol oxidation with tert-butyl hydroperoxide (TBHP). First, iron oxide magnetic nanoparticles (Fe₃O₄) were prepared and finally coated with a thin layer of gold. Structure and composition of Fe₃O₄@Au nanocatalyst were characterized by XRD, TGA, and FT-IR analysis. Size and morphology and size of particles were determined through TEM. Surface properties and topographies of coated nanoparticles were investigated by the AFM technique. The magnetic properties of Fe₃O₄ and Fe₃O₄@Au nanoparticles were measured by VSM technique. After confirming the structure of gold-coated magnetic ION, its performance for the oxidation of various aliphatic and aromatic alcohols with TBHP was studied in water. Finally, the reusability of Fe₃O₄@Au nanocatalyst was evaluated after five consecutive cycles in the 4-methoxybenzyl alcohol oxidation. The measured results revealed that the gold-coated iron oxide magnetic nanoparticles can be reused well in the oxidation processes of alcohols with high efficiency.