In situ loading of gold nanoparticles on Fe3O4@SiO2 magnetic nanocomposites and their high catalytic activity

Abstract

In this work, a facile approach was successfully developed for in situ catalyzing Au nanoparticles loaded on Fe₃O₄@SiO₂ magnetic nanospheres via Sn²⁺ linkage and reduction. After the Fe₃O₄@SiO₂ MNPs were first prepared via a sol–gel process, only one step was needed to synthesize the Fe₃O₄@SiO₂–Au magnetic nanocomposites (Fe₃O₄@SiO₂–Au MNCs), so that both the synthesis step and the reaction cost were remarkably decreased. Significantly, the as-synthesized Fe₃O₄@SiO₂–Au MNCs showed high performance in the catalytic reduction of 4-nitrophenol to 4-aminophenol and could be reused for several cycles with convenient magnetic separability. This approach provided a useful platform based on Fe₃O₄@SiO₂ MNPs for the fabrication of Au or other noble metal magnetic nanocatalysts, which would be very useful in various catalytic reductions.