H3PW12O40 anchored on graphene-grafted silica-coated MnFe2O4 as magnetic catalyst for Mannich reaction

In this study, a three-component nanocomposite consisted of graphene, manganese ferrite and phosphotungstic acid (PTA) has been prepared. This composite, which is designated as Graphene/MnFe 2 O 4 @PTA, was synthesized through anchoring of PTA–imidazolium ionic liquid on magnetic graphene sheets. The structural and magnetic properties of the fabricated nanocomposite were studied by employing FT-IR, SEM, EDX, TEM, ICP, VSM, P-XRD and BET techniques. The synthesized magnetic nanocomposite was examined as an efficient and recyclable acidic catalyst for Mannich reaction under solvent-free conditions. The products of this reaction, which are an important class of potentially bioactive compounds, were obtained with good to excellent yields, and the catalyst could be readily recycled without any significant loss of its activity.