One-pot gradient solvothermal synthesis of Au–Fe3O4 hybrid nanoparticles for magnetically recyclable catalytic applications

Abstract

Au–Fe₃O₄ hybrid nanoparticles (NPs) are successfully synthesized by a one-pot process which is based on the gradient solvothermal process. The key structural feature of the as-prepared Au–Fe₃O₄ hybrid NPs is that a strong metal–oxide interaction exists at the interface due to the epitaxial growth of Fe₃O₄ on Au. Then they show excellent catalytic activity for the reduction of 4-nitrophenol and 2-nitroaniline in the presence of NaBH₄. Due to the superior saturation magnetization (up to 63.532 emu g⁻¹), the Au–Fe₃O₄ hybrid NPs can be easily recycled by a magnet. A possible synthetic mechanism of the Au–Fe₃O₄ hybrid NPs has been proposed. This work may provide a solution to the problems encountered during the large-scale preparation and subsequent practical application of these kind of hybrid nanostructured materials.