Facile synthesis of bifunctional Fe3O4/Au nanocomposite and their application in catalytic reduction of 4-nitrophenol

Abstract In this paper, we report a simple, facile and efficient method to synthesize the bifunctional Fe 3 O 4 /Au nanocomposites by the direct reduction of HAuCl 4 in the presence of carboxylate functionalized Fe 3 O 4 particles which are prepared by a modified solvothermal approach. This facile synthesis route avoids the use of toxic reagent and further surface modification on the Fe 3 O 4 surface. The obtained bifunctional Fe 3 O 4 /Au nanocomposites are characterized by HRTEM, EDX, XRD, UV–vis, and SQUID. The results indicate that every as-prepared Fe 3 O 4 /Au nanocomposites contain numerous Au nanoparticles with an average size of 6 nm around Fe 3 O 4 spheres (260 nm). The bifunctional Fe 3 O 4 /Au nanocomposites exhibit high saturation magnetization (58 emu/g) and high performance in catalytic reduction of 4-nitrophenol (0.05 mg of catalyst with conversion of 95% in 8 min). Furthermore, the Fe 3 O 4 /Au catalysts show convenient magnetic separability and good reusability.