Silver Nanoparticles Engineered β-Cyclodextrin/γ-Fe2O3@ Hydroxyapatite Composite: Efficient, Green and Magnetically Retrievable Nanocatalyst for the Aqueous Reduction of Nitroarenes.

Abstract: Ag nanoparticles incorporated β-cyclodextrin conjugated magnetic hydroxyapatite, γ-Fe2O3@HAp-CD.Ag was conveniently synthesized via the grafting of β-cyclodextrin moieties on the hydroxyapatite surface, followed by reacting of the nanocomposite, γ-Fe2O3, with silver nitrate and then its reduction with sodium borohydride. The cavity of β-cyclodextrin units as host material can stabilize the Ag nanoparticles (particles size: 12–14 nm) effectively and prevent their aggregation and separation from the surface. The nanocomposite obtained appears to have an organized structure, with a magnetic γ-Fe2O3 core surrounded by a layer-structured coating shell. The structure and composition of the nanocomposite were confirmed by FT-IR, FE-SEM, TEM, TGA, XRD, EDS, BET, and VSM. This catalytic system selectively reduces the nitro group even in the presence of other sensitive functional groups in good to excellent yields (85–98%).The organometallic nanocatalyst was easily removed from solution using an external magnet and was successfully examined for five runs, with a slight loss of catalytic activity.Graphical Abstract: <graphic></graphic> [ABSTRACT FROM AUTHOR]